The Koktokay mine and hydropower plant in China’s Xinjiang Uygur autonomous region were once top secret facilities. The installations provided rare minerals that were essential for the country's aerospace and defence industries from the 1950s until the late 1990s. Among the projects it supplied were those to develop atomic and hydrogen bombs. The hydropower facility now supplies energy to nearby towns and the disused mine has become part of the Koktokay National Geopark.