2. Pavlopetri in Peloponnese, Greece

Photo by Spiridon Ion Cepleanu via Wikimedia Commons

Of all the underwater cities to have been discovered, Pavlopetri was the first. This town, likely Mycenaean, was submerged in 1000 BC probably by an earthquake or tsunami. The site is a protected under UNESCO’s Convention on the Protection of the Underwater Cultural Heritage. The 30,000 square meter site comes replete with streets, courtyards, buildings, graves and tombs still in evidence, along with possible monumental structures.