One of the most interesting dive sites in the Athens, is called the well of Vouliagmeni. It is one of the southern seaside suburb of Athens in the Saronic Gulf. The area formed by rocky soils on steep plunge in the sea and forms, picturesque small bays. In general the region is peculiar geological features. It is well-known for its thermal baths, the lake of Vouliagmeni, is 50 meters from the sea, but it has sweet water which gushes from underground hot springs. The depths in Lake Vouliagmeni is too large and area sources are not fully explored because of the depth and labyrinthine underwater caves.