Underwater Cities in Cuba

Havana, Cuba:
 A team of scientists continues to explore megalithic ruins found in the Yucatan Channel near Cuba. They have found evidence of an extensive urban environment stretching for miles along the ocean shore. Some believe that the civilization that inhabited these predates all known ancient American cultures. So far, only computer models of this mysterious underwater city exist.

North Sea, Europe: A lost natural landscape was found recently under the North Sea, once occupied by human hunter-gatherers over 10,000 years ago. What were once rivers, lakes and oceans are
 now all at the bottom of the sea, only made
 known through digital mapping.
 Scientists theorize that this amazingly
well-preserved landscape was at the heart
of an ancient civilization spread across Europe.

Atlantis, Antarctica? Over a hundred years ago, a museum curator in Istanbul made a remarkable discovery. Examining an ancient map on gazelle skin, he found a location marking a mountain chain where Antarctica is today. This map is, amazingly, one of many pieces of evidence people have used to try and claim that, in fact, Antarctica is the fabled lost continent of Atlantis. Other evidence
includes the recent discovery (via sonar technology) of land under Antarctica as well as the mapping systems used by ancient cartographers, which suggest Atlantis might have been located far from the Mediterranean Sea.