Still more evidence of a catastrophic event in the earth’s history. Can anyone say “giant flood?”
But cold water has been poured on the idea by internet search giant Google, which says it is highly unlikely.
The grid is situated about 620 miles off west Africa in an area called the Madeira Abyssal Plane.
It consists of a series of cross-cross lines within a rectangluar boundary about 3.5 miles down.
It was spotted by Bernie Bamford from Chester using a underwater exploration tool Google Ocean.
Mr Bamford says the image looks like a "man-made aerial map" of a city.
Dr Charles Orser, curator of historical archaeology at New York State University has described the find as "fascinating."
He said: "The site is one of the most prominent places for the proposed location of Atlantis, as described by the ancient Greek philosopher Plato.
Even if it turns out to be geographical, it definitely deserves a closer look."
However, Google are adament the grid-like image has nothing to do with Atlantis.
A spokeswoman, said: "It's true that many amazing discoveries have been made in Google Earth.
"In this case, however, the image is an artifact of the data collection process, not the city of Atlantis.
"Boats use sonar to take measurements of the seafloor and the lines shown reflect the path of the boat as it gathers the data."
According to Plato's account, written around 355 BC, the city of Atlantis sank to the bottom of the ocean in around 9,700 BC after a huge earthquake.
Many people believe Plato's story is historically accurate but claim he has got the location wrong.
As a result, the search for the fabled city has spanned the globe. Other suggested sites include the Mediterranean, the Black Sea and the Caribbean.
