Thonis, the legendary port city that served as an entryway to the Egyptian empire, was long considered to be a myth. The tales of its immense power and vast riches conflicted with the evidence of its existence—mainly that there was none. Cities of such grandeur do not typically disappear off the face of the earth. This one, however, did just that. Via the Altlantic:
Sometime around the 8th century AD, Thonis sank into the sea. Most scientists believe that a combination of factors contributed to the cataclysm: a rise in sea level, coupled with a sudden collapse of the sediment-heavy earth on which the city was built. Whatever the causes, though, the results were clear: Heracleion—Thonis—essentially collapsed into itself. The city built upon the water plunged into it.
We know this thanks to the efforts of underwater archeologist Franck Goddio. The legendary french excavator led a team of divers and scientists who conducted a four year geological survey of the expansive area where ancient reports suggest the city once sat. In 2000, they finally found it in the eerie underwater graveyard that silenced the once bustling metropolis. Now, years later, video of their tremendous discovery has finally been released.
Although short, the significance of these images can not be overstated. Watch the process of one of the most monumentous archeological discoveries of the modern era below.