Dieng Volcanic Complex is on the Dieng Plateau in the Central Java, Indonesia, as a complex of volcanoes. The volcanic complex consists of two or more of stratovolcanoes, more than 20 small craters and Pleistocene-to-Holocene age volcanic cones. It covers over 6 × 14 km area. The Prahu stratovolcano was truncated by a large Pleistocene caldera and then filled by parasitic cones, lava domes and craters which is 120 Celsius . Some of them are turned into lakes. Toxic volcanic gas has caused fatalities and is a hazard at several craters. On 20 February 1979 149 people died of gas poisoning in Pekisaran village on the plateau near the Sinila crater. The area is also a major geothermal project.