Pavlopetri Peloponnese, Greece
The lost city Pavlopetri Peloponnese was first discovered in 1967 by Dr. Nicholas Flemming. The city was mapped the following year by a team from Cambridge, and they made a shocking discovery. This ancient city, filled with ruins and various structures, was dated back to the Mycenaean period, 1600 to 1100 BC. However, later studies suggest it could have been first inhabited in 2800 BC. This easily makes Pavlopetri Peloponnese one of the oldest cities ever discovered underwater, and it’s certainly one of the oldest cities on this list!