In Lake Berryessa, the United States, is located the largest outlet in the world: a real gap that makes the body of water in California a attraction unique in the world. It is a kind of ravine that gives the impression to swallow everything around him.
It is not a natural phenomenon, but the result of a engineering work: the huge crater is nothing more than a spillway, a trick that has been adopted to prevent the surrounding area to go under water. A dam whose story, for another, it is quite old, since it was built between 1953 and 1957