For centuries the story of Atlantis has captured the imagination - a fabled city of great beauty, culture and wealth that was suddenly swallowed up by the ocean.
Its location - or at least the source of the legend - remained a tantalising mystery. Was it really in the Mediterranean and not in the Atlantic at all?
Some claim its ruins lie beneath the waves off the coast of Cornwall. Others say they've been found in the Black Sea.
But for a few hours this week, experts hoped the riddle may finally have been solved.
More than six hundred miles off West Africa and more than three miles down lay a mysterious grid of lines that resembled the streets of a city.