These foundations were once part of a building in ancient Greece. Over thousands of years, active faults have lowered the land and the foundations have sunk below sea level. Geology can have a big impact on relatively short timescales.
(c) Geology for Global Development
Matt Herod
Cool!! I love the intersection between geology and the classics. Check out this post at my old blog on the rediscovery of Ithaca. http://globalgeology.blogspot.ca/2012/06/odyssey-and-geology-search-for-ithaca.html