Yakushima, one of the Ōsumi Islands, is an island of about 500 km² and roughly 15,000 islanders to the south of Kyūshū in Kagoshima Prefecture, Japan. The Vincennes Strait (Yakushima Kaikyō) separates it from Tanegashima. The highest point on the island is Miyanoura-dake at 1,935 metres (6,360 ft). It is covered in dense forest noted especially for old growth Cryptomeria trees known as Sugi in Japan and magnificent Rhododendrons.
Yakushima's unique remnant of a warm-temperate ancient forest is a natural World Heritage Site since 1993. In the Wilderness core area (12.19 square kilometres (3,010 acres)) of the World Heritage Site, no records of past tree cutting can be traced. Yakushima is Japan's wettest place, and precipitation in Yakushima is one of the world's highest at 4,000 to 10,000 mm. It is said to rain "35 days a month". There are drier periods in autumn and winter, while heaviest downpours occur in spring and summer often accompanied by landslides. It is the southernmost place in Japan where there is snow in the mountains, often for months, while the ocean temperature is never below 19°C.
The Yakusugi Forest is visited by 300,000 tourists every year. It is said to have inspired the forest setting in Hayao Miyazaki's film Princess Mononoke. The island was also seen in the 1996 movie Rebirth of Mothra where Mothra Leo laid his cocoons on one of the trees there.
The island has been a test site for Honda's hydrogen fuel cell vehicle research. Yakushima's electricity is more than 50% hydroelectric, and surplus power has been used to produce hydrogen gas in a small experiment by Kagoshima University. There are no hydrogen cars stationed on the island but a few electric cars are run by the municipality.
Administratively, the whole island is the town of Yakushima. The town also serves the neighbouring Kuchinoerabujima.
Yakushima Airport serves the island.