It was first described by Platon in 330 BC, and now Atlantis may have been finally found.
In a new documentary, experts from Merlin Burrows, a land and sea search team based in Harrogate, claim they have discovered the ruins of Atlantis off the coast of Spain.
Using data from commercial satellites, the researchers believe that the lost city could be in Spain's Doñana National Park.
Speaking to Live Science, Bruce Blackburn, CEO of Merlin Burrows, said: "Obviously, it's a very bold thing to say.
"Everybody is going to have [one of] two opinions. One is that 'This is great. Let's have a look at it, 'and one will be' That's a load of rubbish. '"
The researchers focused on Spain having read two of Plato's dialogues on Atlantis.
Mr Blackburn explained: "The Atlantis cities, which are very detailed in Plato's writing, are really there for everyone to see."
The findings will be revealed in an upcoming documentary called Atlantica – although it's unclear when this will air.
However, not everyone is so convinced that this is really Atlantis.
Speaking to Live Science, Professor Ken Feder, an expert in anthropology at Central Connecticut State University, said: "Bless their hearts – if they're right about this, that would be awesome.
"But here's my problem: As an archeologist, I know that I always need to be in the company of my bulls ** t detector.
"And these guys, they have done just about everything they possibly can to set off my bulls ** t detector."