Denshima

Denshima (デン島), also known as Yuze (湯瀬), is an uninhabited volcanic pillar located in the Ōsumi Islands and belonging to Kagoshima Prefecture, Japan.

Geography
Denshima is located roughly equidistant between Iōjima and Kuroshima. The island is an exposed and highly eroded portion of lava dome associated with the submarine Kikai Caldera, a stratovolcano rising from the ocean floor. It consists of three large rocks, separated by very narrow channels, with a maximum height of 58 m above sea level, and a smaller rock, just breaching the ocean surface, to one side.