A strange occurrence in nature, not only is the stony bottom sea composed of fresh water but it's also a very largely deep hot spring. Falling under the protection of the "Arcadian Peace Treaty", many shinobi from Iwagakure are allowed by the Arcadian council to spend their leisure time here. Some have even been noted to have erected small boats and use them as personal islands of solitude when they want to get away from it all or simply have a good time. If one can brave the high temperatures, rare diamonds, pearls and other precious stones grow as plentiful as the grass and trees above. The sea is said to end in a waterfall that falls into the very depths of the earth. How the sea allows for life in such a harsh environment is a mystery.