Kawah Ijen (2386 m) is an active composite volcano located within the Pleistocene Ijen Caldera (old volcanic crater), at the easternmost part of Java island. The visible superficial manifestations of the hydrothermal system of Kawah Ijen's activity consist of the world's largest hyperacidic lake on Earth, a few thermal discharges and crater fumaroles which produce significant amounts of native sulfur. The Ijen caldera complex measures approximately 210 km2. Its name is linked to that of the only currently active volcano within the caldera, Kawah Ijen. The caldera contains more than 15 post caldera volcanic cones making it one of the top recommended area in the world for stunning volcanic scenery.