Ikishima

Ikishima is a small, uninhabited island located in the Seto Inland Sea, off the coast of Hiroshima Prefecture, Japan. It is part of the Oki Islands, a group of islands that stretch from the southern coast of Honshu to the northern coast of Shikoku. Ikishima is known for its unique geological features, including a large number of lava tubes and lava caves, which are a result of volcanic activity in the region. The island is also home to a variety of plant and animal species, including several endangered ones.

The island was formed during the Pleistocene epoch, when volcanic activity in the region created a series of lava flows that eventually cooled and solidified to form the island. Over time, erosion and weathering have shaped the island's landscape, creating the lava tubes and caves that are now a major attraction for visitors.

Ikishima is not accessible to the public due to its remote location and the presence of lava tubes and caves that are not safe for visitors to explore. However, the island is a popular destination for hikers and nature enthusiasts who visit the nearby Oki Islands. The island is also a protected area, with strict regulations in place to preserve its unique ecosystem and geological features.

In recent years, there has been growing interest in the potential for geothermal energy on Ikishima. The island's volcanic activity has created a number of hot springs and geothermal features, which could potentially be harnessed for energy production. However, the environmental impact of such development is a major concern, and the feasibility of geothermal energy on Ikishima remains an area of ongoing research and debate.