At first, researchers thought Por-Bajin was an ancient fortress of the Uighur Empire, nomads who ruled southern Siberia and Mongolia from 742–848. It’s constructed with a Chinese architectural style from that time. However, it’s so out of the way of trade routes and other settlements that competing theories eventually arose. Maybe it was a monastery, a summer palace, a memorial for a ruler, or an observatory for the stars. Evidence is accumulating that a Buddhist monastery was at the center of the complex, although only a few artifacts have been unearthed.
The complex does not appear to have been inhabited for long. Archaeologists found indications of earthquakes that may have caused a fire that burned some of the original site. However, the fire appears to have occurred after the island was abandoned for reasons unknown.
8Etruscan Underground Pyramids
“Most likely, the answer waits at the bottom,” said archaeologist Claudio Bizzarri of the extraordinary mystery posed by the discovery of an Etruscan pyramid underneath the medieval city of Orvieto, Italy. “The problem is we don’t really know how much we have to dig to get down there.” The excavators found it almost four years ago and still don’t have a clue what awaits them.