Back in the early 1980s, the famous ocean explorer Captain Jacques Yves Cousteau and his team paid a visit to the island of Sipadan, off the coast of Borneo to film a documentary about its crystalline waters. One of the highlights in this film was a mysterious underwater cave in which they found lots of bones and skeletons of sea turtles. For lack of a better explanation, Cousteau suggested that perhaps old sea turtles just went there to die peacefully. In reality, the turtles enter the cavern by accident and then get lost in the labyrinth of the tunnels. Unable to find an exit, they eventually become disorientated and drown.

Photo credit: Borut Furlan