Legend has it that hidden under the waves of the Atlantic Ocean was a once highly civilized state called Atlantis. On the other side of the world, a similar tale persists that an ancient city is buried deep in a lake in Yunnan, a border province in Southwest China.

But unlike the mythical tale of Atlantis, the submerged secret in Fuxian Lake near Kunming , capital city of Yunnan, may be a reality, as divers continue finding proof of its existence.

Eight years ago, a local diver named Geng Wei saw a slew of large flat rocks scattered under the water 300 metres away from the eastern bank of Fuxian Lake.

"These boulders have regular shape, each with more than 1.4 square metres. Many of them are broken into half, with clear clefts," said the swarthy man, who led a large exploration into the lake recently.

The seven-day underwater expedition that started last Friday and ends today is a second one at the lake in the past five years. The first exploration in 2001 was prompted after Geng submitted his discoveries to the local government.