Scientists say they may have discovered the lost city of Atlantis buried deep under the marshlands of southern Spain.

The legendary city is believed to have been "swallowed up by the sea," as the Greek philosopher Plato so famously put it 2,400 years ago.

He wrote of a great city destroyed by floodwaters following an earthquake deep under the sea — an image that resonates at a time when Japan is struggling to recover from a devastating earthquake and tsunami off its northeast coast.

A National Geographic television special that aired on Sunday details the work of American, Canadian and Spanish scientists as they attempt to prove Atlantis existed by following up on space satellite images showing unusual features in an area just north of Cadiz.

The area is near the Straits of Gibraltar — widely thought to be the "Pillars of Hercules" Plato mentioned in his description of the location of Atlantis.

The team is led by archaeologist Richard Freund of the University of Hartford in Connecticut. It used satellite photography, ground-penetrating radar and underwater technology to look for proof of the city's existence.

"This is the power of tsunamis," Freund told Reuters. "It is just so hard to understand that it can wipe out 60 miles (almost 100 kilometres) inland, and that's pretty much what we're talking about."

Freund's team also includes geophysicist Paul Bauman from the engineering firm WorleyParsons in Calgary and geographer Philip Reeder of the University of South Florida.

Sensor readings suggest the presence of a communal oven and possibly canals, Bauman told Postmedia News.

Freund told the Hartford Courant newspaper that the Cadiz site is the best possible candidate for the location of Atlantis that's ever been discovered, with the most amount of evidence backing it up.

The researchers say they also discovered a series of mysterious memorial cities in central Spain, seemingly modelled on Atlantis, leading them to conclude those who survived the tsunami fled Atlantis and built new cities inland.