The world is filled with ancient monuments built by master craftsmen in order to honor everything from kings and presidents to religious figures. And although most of these landmarks have been carefully studied and researched by scientists and historians, some are simply so old, incomplete, or obscure that we still don’t know very much about why they were built or what purpose they served. The following are 10 world landmarks that, whether by intention or simply due to the passage of time, continue to baffle the people who study them.
2. The Great Sphinx of Giza
Despite its reputation as one of the most famous monuments of antiquity, there is still very little known about the Great Sphinx of Giza. Egyptologists might have a small understanding of why the statue was built, but when, how, and by who is still shrouded in mystery. The pharaoh Khafra is the main suspect, which would date the structure back to around 2500 BC, but other scientists have argued that evidence of water erosion of the statue suggests that it is much older and perhaps even predated the dynastic era of the Egyptians. This theory has few modern adherents, but if true it would mean the Great Sphinx of Giza is even more mysterious than previously believed.
3. The Georgia Guidestones
For all their controversy, very little is known about who built the Guidestones or what their true purpose is. R.C. Christian claimed he represented an independent organization when he commissioned the landmark, but neither he nor his group has spoken up since its construction. Since the monument was built during the height of the Cold War, one popular theory about the group’s intentions is that the Guidestones were to serve as a primer for how to rebuild society in the aftermath of a nuclear holocaust.
4. The Easter Island Moai
While there is a fairly solid consensus on why the Moai were erected, how the islanders did it is still up for debate. The average Moai weighs several tons, and for years scientists were at a loss to describe how the monuments were transported from Rano Raraku, where most of them were constructed, to their various locations around the island. In recent years, the most popular theory is that the builders used wooden sleds and log rollers to move the Moai, an answer that would also explain how the once verdant island became almost totally barren due to deforestation.
Most scientists agree that Sacsayhuaman served as a kind of fortress of barrier wall, but this has been disputed. The strange shape and angles of the wall have led some speculate that it may have had a more symbolic function, one example being that the wall, when seen next to Cuzco from above, forms the shape of the head of a Cougar. Even more mysterious than the monument’s use, though, are the methods that were used in its construction. Like most Inca stone works, Sacsayhuaman was built with large stones that fit together so perfectly that not even a sheet of paper can be placed in the gaps between them. Just how the Incas managed such expert placements, or, for that matter, how they managed to transport and lift the heavy hunks of stone, is still not fully known.
6. Goseck Circle
The monument’s careful construction has led many scientists to believe that the Goseck Circle was built to serve as some kind of primitive solar or lunar calendar, but its exact use is still a source of debate. Evidence has shown that a so-called “solar cult” was widespread in ancient Europe. This has led to speculation that the Circle was used in some kind of ritual, perhaps even in conjunction with human sacrifice. This hypothesis has yet to be proven, but archeologists have uncovered several human bones, including a headless skeleton, just outside the palisade walls.
7. The Nazca Lines
Scientists know who made the Nazca Lines and how they did it, but they still don’t know why. The most popular and reasonable hypothesis is that the lines must have figured in the Nazca people’s religious beliefs, and that they made the designs as offerings to the gods, who would’ve been able to see them from the heavens. Still, other scientists argue that the lines are evidence of massive looms that the Nazcas used to make textiles, and one investigator has even made the preposterous claim that they are the remnants of ancient airfields used by a vanished, technologically advanced society.
8. The Yonaguni Monument
The ongoing debate surrounding Yonaguni centers on one key subject: is the monument a natural phenomenon, or is it man-made? Scientists have long argued that millennia of strong currents and erosion have carved the formations out of the ocean floor, and they point to the fact that the monument is all one piece of solid rock as proof that it was not assembled by a builder. Others, though, point to the many straight edges, square corners and 90-degree angles of the formation as proof that it’s artificial. They often cite one formation in particular, a section of rock that resembles a crude carving of a human face, as evidence. If they are right, then an even more interesting mystery presents itself: who constructed the Yonaguni Monument, and for what purpose?
Archeologists know Newgrange was used as a tomb, but why and for who still remains a mystery. The painstaking design needed to guarantee that the yearly solstice event occurs suggests that the site was held in high regard, but other than the obvious hypothesis that the sun featured prominently in the mythology of the builders, scientists are at a loss to describe the true reason for Newgrange’s construction.
10. The Cahokia Mounds
Although scientists are constantly discovering new information about the Cohokia community, the biggest mystery that remains is which modern Indian tribe is descended from the residents of the ancient city, as well as just what it was that caused them to abandon their settlement.