Yonaguni, Japan
Coordinates: 24°25'58"N 123°0'29"E
Underwater stone complex located near Japanese island of Yonaguni. It seems it was either erected before last ice age meltdown or our ancestors found the way how to build below the water level.
Last time this terrain was a dry land ca. 14.000 years ago.
Last time this terrain was a dry land ca. 14.000 years ago.
Title photo by Masahiro Kaji [CC-BY-SA-3.0-2.5-2.0-1.0], via Wikimedia Commons