---
title: 3 Unsolved Ancient Engineering Mysteries
description: "Engineering is an old profession. From the dawn of history, people have been using numbers to perform feats that otherwise might seem impossible – Aristotle is said to have lifted an entire ship out of a harbor by himself, using only pulleys and ropes. We've put people on the moon, and the bottom of the ocean, and we even have tiny balls of electricity running through wires to put this video on your screen. At the end of the day, it's all just a math problem, isn't it?\n\nToday, we'd like to delve a bit into the history of engineering – specifically, the murky history of it. The past is full of moments with gaps in the historical record, and engineering is no exception. We have buildings, contraptions, and even, as you'll see, sounds that defy easy explanation. These are some unsolved ancient engineering mysteries.\n\n## The Baghdad Battery\n\nStarting our list off, we have the Baghdad Battery. In 1936, an Austrian archaeologist named Wilhelm Konig was excavating a site in Khujut Rabu, a village just outside of Baghdad in Iraq. There, in an old grave covered by a stone slab, he discovered a set of three artifacts: a clay pot, six inches tall; a hollow copper cylinder; and a single iron rod. These artifacts fit together, with the rod going into the copper cylinder, and the cylinder going into the jar.\n\nKonig was intrigued by this, and speculated that the object was an ancient prototype of a battery, a so-called galvanic cell, capable of holding an electric charge when all put together, along with an acidic agent like wine or vinegar. The fact that the iron appeared to be corroded, indicating such a liquid was present, seemed to support that claim. Konig hypothesized that the purpose of such a battery was for electroplating gold onto silver objects.\n\nNow, this hypothesis is near-universally rejected, for a number of reasons. Firstly, Konig made a number of claims that didn't line up, such as saying the artifacts were from the Parthian Empire, even though the style of the pottery was from the later Sassanid Persian Empire. Second, when the pieces are all together, there's no way to connect them to complete the electrical circuit, making it pretty useless as a battery. And third, even if it was possible to use them to electroplate gold and silver together, there are no known electroplated objects that have been found from the same time to support the hypothesis.\n\nSo, why do we include it? What was it actually used for? Currently, the tentative explanation is that the objects were used to store scrolls, which were then buried with someone who died, perhaps a priest. Considering the jars were found in an old grave, along with several hundred beads and other artifacts, this seems plausible.\n\nNevertheless, there's still a bit of intrigue here. The TV show *MythBusters* did an episode testing the Baghdad Battery, making recreations of it to see if it could actually produce an electric charge. And, it turns out, it could. It's still almost certain that whoever created it didn't know this, and couldn't use it for anything practical, meaning that whoever created the Baghdad Battery discovered batteries by accident. Massive coincidence or not, that's something you don't see very often.\n\n## The Antikythera Mechanism\n\nIn 1900, a Roman-era shipwreck was discovered by sponge divers off the coast of the Greek island of Antikythera. The Greek navy proceeded to explore the wreck, recovering various artifacts such as coins, statues, and more, dating back over two thousand years. One of those artifacts was a worn down hunk of corroded bronze, considerably ravaged by the passage of time.\n\nAt first, the artifact was ignored in favor of the statues and coins, which were easier to decipher, and so it was placed in storage for over a year. But when they got around to examining it, it was revealed that there was more to this lump of waterlogged rust than met the eye.\n\nThe Antikythera Mechanism is an ancient clockwork device, i.e. one powered by gears. Specifically, it's an orrery, a mechanical model of the Solar System that helps to predict the positions of the planets and the moons, decades in advance. It could tell you the phases of the moon and even predict when eclipses would happen. You put in a date, and it spits out the result. In short, it's a computer. A two-thousand year old analogue computer. Isn't that something?\n\nThe original artifact is rather degraded, making it hard to decipher just by looking at it. It doesn't help that it's in several pieces from sitting on the bottom of the ocean for two millennia. But, just like the person who created this device, we have technology. Using various advanced methods, including x-ray imaging, researchers have managed to recreate what the device probably would've looked like, and how it worked.\n\nThe device is currently believed to have consisted of 37 bronze gears, precisely measured to follow the movements of both the Sun and the Moon, even through the moon's irregular orbits. There's some speculation that the device also had an additional segment, for decoding the movements of the planets, as well – Mercury, Venus, Mars, Jupiter, and Saturn. The others weren't known about yet.\n\nThe mechanism itself was quite complex. There was a dial for setting the date, and the whole machine was powered by a hand crank, which would turn a gear linked to the front dial. To set the year, one used two scales – one with 365 days and 12 months, and the other with 360 days and 12 zodiac signs. It had 360 because the old calendar used in the mechanism had 12 months of 30 days each, with 5 days left over. If you needed to clarify a date or a year, the device also included a handy built-in calendar on the back side. There's even separate dials to account for leap years; not automatically, amazing as that would've been. But they are there.\n\nSo now to the big question: what's the story? Who made it, and where, and why, and how? All good questions, some with tentative answers. There's no definitive answer as to the creators, except that they were probably Greek scientists who were well-versed in astronomy. The device was found off an island in southern Greece, but its place of origin could variously be Rhodes, Corinth, northwestern Greece, or even a Greek colony in Sicily.\n\nAside from that, the rest of the story is a bit shrouded in mystery. The research, however, is far from complete, and it's possible more of the puzzle will come together over time; experts are continuing to dive in the underwater spot where the device was originally found, hoping to discover more clues as to its origins. Soon, perhaps, we'll have more answers.\n\n## Chichen Itza\n\nThe last entry we have for this list is a bit unusual. Bear with us as we go to Mexico's Yucatan Peninsula, the home of the Mayan civilization. The Maya were a sophisticated culture, having comprehensive understandings of astronomy, architecture, and many other mathematical concepts. One of the greatest Mayan cities was Chichen Itza; it was one of the largest pre-Columbian cities in Mesoamerica and is today the site of many old Mayan monuments.\n\nOne of those monuments is the Temple of Kukulcán, variously known as El Castillo, La Pirámide, or just Kukulcán. It's a step pyramid, built between the 8th and 12th century – not particularly ancient, mind you, but old all the same. The pyramid was a temple dedicated to the Mayan deity of, take a guess, Kukulcán, who bears a close resemblance to the Aztec god of Quetzalcoatl.\n\nBut it's not so much the construction of the pyramid that intrigues. Rather, there's some ancillary things that pique one's interest. To start with, during the spring and autumn equinoxes, the sun flares off one side of the pyramid, casting shadows that appear to resemble snakes crawling down the side of the temple. Is that on purpose? The Mayans were known to construct temples, or parts of them, deliberately aligned or oriented based on celestial events. So it's possible, although it again could just be coincidence.\n\nHowever, there is another aspect of this pyramid that catches people's eyes. Or ears, in this case. You see, if you're standing in front of the pyramid, and then you clap your hands, the sound travels back to you sounding rather like the chirping of a bird; a quetzal, to be specific. The technical explanation is that the sound waves travel up the side of the pyramid, each one returning to the listener at a later time than before as it bounces off the limestone steps. Because the waves travel at an angle, and because of math, the later echoes decline in frequency, creating a chirping sound.\n\nAn interesting effect, to be sure, but some researchers have argued that this characteristic is not accidental, and that the temple was built specifically to scatter and reflect sound waves in such a way to mimic the sound of a native bird. Such a claim is naturally difficult to prove, but if the Mayans worked out astronomy, it's possible they could work out sound waves in architecture, too, and they certainly had attention to detail when it came to buildings. Again, it could just be a massive coincidence, but who's to say?\n\n## Key Takeaways\n\n- The Baghdad Battery, discovered in 1936, is an ancient artifact that may have been used to store scrolls.\n- The Antikythera Mechanism, found in 1900, is an ancient analogue computer that predicted celestial movements.\n- The Temple of Kukulcán in Chichen Itza produces a bird-like sound when clapped, possibly by design.\n- The Antikythera Mechanism's creators were likely Greek scientists with advanced knowledge of astronomy.\n- The Baghdad Battery could generate an electric charge, but its creators likely did not know its purpose.\n\n## Frequently Asked Questions\n\n### What is the Baghdad Battery?\n\nThe Baghdad Battery is a set of three artifacts discovered in 1936 in Khujut Rabu, Iraq, consisting of a clay pot, a hollow copper cylinder, and an iron rod. It was hypothesized to be an ancient battery, but this theory is widely rejected.\n\n### Who discovered the Baghdad Battery?\n\nThe Baghdad Battery was discovered by an Austrian archaeologist named Wilhelm Konig in 1936.\n\n### What was the original purpose of the Baghdad Battery?\n\nThe original purpose of the Baghdad Battery is uncertain, but it is tentatively believed to have been used to store scrolls, which were then buried with someone who died, perhaps a priest.\n\n### What is the Antikythera Mechanism?\n\nThe Antikythera Mechanism is an ancient Greek analogue computer used to predict astronomical positions and eclipses. It was discovered in a Roman-era shipwreck off the coast of the Greek island of Antikythera in 1900.\n\n### How does the Antikythera Mechanism work?\n\nThe Antikythera Mechanism consists of 37 bronze gears that follow the movements of the Sun and the Moon. It includes dials for setting the date and a hand crank to power the device, with scales for 365 days and 12 months, and 360 days and 12 zodiac signs.\n\n### Who created the Antikythera Mechanism?\n\nThe creators of the Antikythera Mechanism are unknown, but they were likely Greek scientists well-versed in astronomy. The device's origin could be Rhodes, Corinth, northwestern Greece, or a Greek colony in Sicily.\n\n### What is the Temple of Kukulcán?\n\nThe Temple of Kukulcán, also known as El Castillo or La Pirámide, is a step pyramid located in Chichen Itza, Mexico. It was built between the 8th and 12th centuries and is dedicated to the Mayan deity Kukulcán.\n\n### What is the significance of the sound effect at the Temple of Kukulcán?\n\nWhen you clap your hands in front of the Temple of Kukulcán, the sound echoes back as a chirping sound, resembling the call of a quetzal bird. Some researchers believe this effect was intentionally designed by the Mayans.\n\n### What happens during the equinoxes at the Temple of Kukulcán?\n\nDuring the spring and autumn equinoxes, the sun casts shadows on the Temple of Kukulcán that appear to resemble snakes crawling down the side of the temple. This could be a deliberate design by the Mayans.\n\n## Sources\n\n- [Original Side Projects video: 3 Unsolved Ancient Engineering Mysteries](https://www.youtube.com/watch?v=pHJL60t1QPo)\n\n## Related Coverage"
url: https://sideprojects.pub/article/3-unsolved-ancient-engineering-mysteries.md
canonical: https://sideprojects.pub/article/3-unsolved-ancient-engineering-mysteries
datePublished: 2026-06-25
dateModified: 2026-06-25
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  - name: Simon Whistler
    url: https://sideprojects.pub/author/simon-whistler
publisher: Side Projects
image: "https://media.sideprojects.pub/cdn-cgi/image/width=1600,height=900,fit=cover,quality=80,format=auto/articles/pHJL60t1QPo/hero.jpg"
type: NewsArticle
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summaryUrl: https://sideprojects.pub/article/3-unsolved-ancient-engineering-mysteries.md.summary.md
---

<!-- aeo:section start="lede" -->
Engineering is an old profession. From the dawn of history, people have been using numbers to perform feats that otherwise might seem impossible – Aristotle is said to have lifted an entire ship out of a harbor by himself, using only pulleys and ropes. We've put people on the moon, and the bottom of the ocean, and we even have tiny balls of electricity running through wires to put this video on your screen. At the end of the day, it's all just a math problem, isn't it?

Today, we'd like to delve a bit into the history of engineering – specifically, the murky history of it. The past is full of moments with gaps in the historical record, and engineering is no exception. We have buildings, contraptions, and even, as you'll see, sounds that defy easy explanation. These are some unsolved ancient engineering mysteries.

<!-- aeo:section end="lede" -->
<!-- aeo:section start="the-baghdad-battery" -->
## The Baghdad Battery

Starting our list off, we have the Baghdad Battery. In 1936, an Austrian archaeologist named Wilhelm Konig was excavating a site in Khujut Rabu, a village just outside of Baghdad in Iraq. There, in an old grave covered by a stone slab, he discovered a set of three artifacts: a clay pot, six inches tall; a hollow copper cylinder; and a single iron rod. These artifacts fit together, with the rod going into the copper cylinder, and the cylinder going into the jar.

Konig was intrigued by this, and speculated that the object was an ancient prototype of a battery, a so-called galvanic cell, capable of holding an electric charge when all put together, along with an acidic agent like wine or vinegar. The fact that the iron appeared to be corroded, indicating such a liquid was present, seemed to support that claim. Konig hypothesized that the purpose of such a battery was for electroplating gold onto silver objects.

Now, this hypothesis is near-universally rejected, for a number of reasons. Firstly, Konig made a number of claims that didn't line up, such as saying the artifacts were from the Parthian Empire, even though the style of the pottery was from the later Sassanid Persian Empire. Second, when the pieces are all together, there's no way to connect them to complete the electrical circuit, making it pretty useless as a battery. And third, even if it was possible to use them to electroplate gold and silver together, there are no known electroplated objects that have been found from the same time to support the hypothesis.

So, why do we include it? What was it actually used for? Currently, the tentative explanation is that the objects were used to store scrolls, which were then buried with someone who died, perhaps a priest. Considering the jars were found in an old grave, along with several hundred beads and other artifacts, this seems plausible.

Nevertheless, there's still a bit of intrigue here. The TV show *MythBusters* did an episode testing the Baghdad Battery, making recreations of it to see if it could actually produce an electric charge. And, it turns out, it could. It's still almost certain that whoever created it didn't know this, and couldn't use it for anything practical, meaning that whoever created the Baghdad Battery discovered batteries by accident. Massive coincidence or not, that's something you don't see very often.

<!-- aeo:section end="the-baghdad-battery" -->
<!-- aeo:section start="the-antikythera-mechanism" -->
## The Antikythera Mechanism

In 1900, a Roman-era shipwreck was discovered by sponge divers off the coast of the Greek island of Antikythera. The Greek navy proceeded to explore the wreck, recovering various artifacts such as coins, statues, and more, dating back over two thousand years. One of those artifacts was a worn down hunk of corroded bronze, considerably ravaged by the passage of time.

At first, the artifact was ignored in favor of the statues and coins, which were easier to decipher, and so it was placed in storage for over a year. But when they got around to examining it, it was revealed that there was more to this lump of waterlogged rust than met the eye.

The Antikythera Mechanism is an ancient clockwork device, i.e. one powered by gears. Specifically, it's an orrery, a mechanical model of the Solar System that helps to predict the positions of the planets and the moons, decades in advance. It could tell you the phases of the moon and even predict when eclipses would happen. You put in a date, and it spits out the result. In short, it's a computer. A two-thousand year old analogue computer. Isn't that something?

The original artifact is rather degraded, making it hard to decipher just by looking at it. It doesn't help that it's in several pieces from sitting on the bottom of the ocean for two millennia. But, just like the person who created this device, we have technology. Using various advanced methods, including x-ray imaging, researchers have managed to recreate what the device probably would've looked like, and how it worked.

The device is currently believed to have consisted of 37 bronze gears, precisely measured to follow the movements of both the Sun and the Moon, even through the moon's irregular orbits. There's some speculation that the device also had an additional segment, for decoding the movements of the planets, as well – Mercury, Venus, Mars, Jupiter, and Saturn. The others weren't known about yet.

The mechanism itself was quite complex. There was a dial for setting the date, and the whole machine was powered by a hand crank, which would turn a gear linked to the front dial. To set the year, one used two scales – one with 365 days and 12 months, and the other with 360 days and 12 zodiac signs. It had 360 because the old calendar used in the mechanism had 12 months of 30 days each, with 5 days left over. If you needed to clarify a date or a year, the device also included a handy built-in calendar on the back side. There's even separate dials to account for leap years; not automatically, amazing as that would've been. But they are there.

So now to the big question: what's the story? Who made it, and where, and why, and how? All good questions, some with tentative answers. There's no definitive answer as to the creators, except that they were probably Greek scientists who were well-versed in astronomy. The device was found off an island in southern Greece, but its place of origin could variously be Rhodes, Corinth, northwestern Greece, or even a Greek colony in Sicily.

Aside from that, the rest of the story is a bit shrouded in mystery. The research, however, is far from complete, and it's possible more of the puzzle will come together over time; experts are continuing to dive in the underwater spot where the device was originally found, hoping to discover more clues as to its origins. Soon, perhaps, we'll have more answers.

<!-- aeo:section end="the-antikythera-mechanism" -->
<!-- aeo:section start="chichen-itza" -->
## Chichen Itza

The last entry we have for this list is a bit unusual. Bear with us as we go to Mexico's Yucatan Peninsula, the home of the Mayan civilization. The Maya were a sophisticated culture, having comprehensive understandings of astronomy, architecture, and many other mathematical concepts. One of the greatest Mayan cities was Chichen Itza; it was one of the largest pre-Columbian cities in Mesoamerica and is today the site of many old Mayan monuments.

One of those monuments is the Temple of Kukulcán, variously known as El Castillo, La Pirámide, or just Kukulcán. It's a step pyramid, built between the 8th and 12th century – not particularly ancient, mind you, but old all the same. The pyramid was a temple dedicated to the Mayan deity of, take a guess, Kukulcán, who bears a close resemblance to the Aztec god of Quetzalcoatl.

But it's not so much the construction of the pyramid that intrigues. Rather, there's some ancillary things that pique one's interest. To start with, during the spring and autumn equinoxes, the sun flares off one side of the pyramid, casting shadows that appear to resemble snakes crawling down the side of the temple. Is that on purpose? The Mayans were known to construct temples, or parts of them, deliberately aligned or oriented based on celestial events. So it's possible, although it again could just be coincidence.

However, there is another aspect of this pyramid that catches people's eyes. Or ears, in this case. You see, if you're standing in front of the pyramid, and then you clap your hands, the sound travels back to you sounding rather like the chirping of a bird; a quetzal, to be specific. The technical explanation is that the sound waves travel up the side of the pyramid, each one returning to the listener at a later time than before as it bounces off the limestone steps. Because the waves travel at an angle, and because of math, the later echoes decline in frequency, creating a chirping sound.

An interesting effect, to be sure, but some researchers have argued that this characteristic is not accidental, and that the temple was built specifically to scatter and reflect sound waves in such a way to mimic the sound of a native bird. Such a claim is naturally difficult to prove, but if the Mayans worked out astronomy, it's possible they could work out sound waves in architecture, too, and they certainly had attention to detail when it came to buildings. Again, it could just be a massive coincidence, but who's to say?

<!-- aeo:section end="chichen-itza" -->
<!-- aeo:section start="key-takeaways" -->
## Key Takeaways

- The Baghdad Battery, discovered in 1936, is an ancient artifact that may have been used to store scrolls.
- The Antikythera Mechanism, found in 1900, is an ancient analogue computer that predicted celestial movements.
- The Temple of Kukulcán in Chichen Itza produces a bird-like sound when clapped, possibly by design.
- The Antikythera Mechanism's creators were likely Greek scientists with advanced knowledge of astronomy.
- The Baghdad Battery could generate an electric charge, but its creators likely did not know its purpose.

<!-- aeo:section end="key-takeaways" -->
<!-- aeo:section start="frequently-asked-questions" -->
## Frequently Asked Questions

### What is the Baghdad Battery?

The Baghdad Battery is a set of three artifacts discovered in 1936 in Khujut Rabu, Iraq, consisting of a clay pot, a hollow copper cylinder, and an iron rod. It was hypothesized to be an ancient battery, but this theory is widely rejected.

### Who discovered the Baghdad Battery?

The Baghdad Battery was discovered by an Austrian archaeologist named Wilhelm Konig in 1936.

### What was the original purpose of the Baghdad Battery?

The original purpose of the Baghdad Battery is uncertain, but it is tentatively believed to have been used to store scrolls, which were then buried with someone who died, perhaps a priest.

### What is the Antikythera Mechanism?

The Antikythera Mechanism is an ancient Greek analogue computer used to predict astronomical positions and eclipses. It was discovered in a Roman-era shipwreck off the coast of the Greek island of Antikythera in 1900.

### How does the Antikythera Mechanism work?

The Antikythera Mechanism consists of 37 bronze gears that follow the movements of the Sun and the Moon. It includes dials for setting the date and a hand crank to power the device, with scales for 365 days and 12 months, and 360 days and 12 zodiac signs.

### Who created the Antikythera Mechanism?

The creators of the Antikythera Mechanism are unknown, but they were likely Greek scientists well-versed in astronomy. The device's origin could be Rhodes, Corinth, northwestern Greece, or a Greek colony in Sicily.

### What is the Temple of Kukulcán?

The Temple of Kukulcán, also known as El Castillo or La Pirámide, is a step pyramid located in Chichen Itza, Mexico. It was built between the 8th and 12th centuries and is dedicated to the Mayan deity Kukulcán.

### What is the significance of the sound effect at the Temple of Kukulcán?

When you clap your hands in front of the Temple of Kukulcán, the sound echoes back as a chirping sound, resembling the call of a quetzal bird. Some researchers believe this effect was intentionally designed by the Mayans.

### What happens during the equinoxes at the Temple of Kukulcán?

During the spring and autumn equinoxes, the sun casts shadows on the Temple of Kukulcán that appear to resemble snakes crawling down the side of the temple. This could be a deliberate design by the Mayans.

<!-- aeo:section end="frequently-asked-questions" -->
<!-- aeo:section start="sources" -->
## Sources

- [Original Side Projects video: 3 Unsolved Ancient Engineering Mysteries](https://www.youtube.com/watch?v=pHJL60t1QPo)

<!-- aeo:section end="sources" -->
<!-- aeo:section start="related-coverage" -->
## Related Coverage
<!-- aeo:section end="related-coverage" -->