Iyang-Argapura twin volcano is a massive complex in East Java, Indonesia, 25 km NW of the university town of Jember. It dominates the landscape between Raung and Lamongan volcanoes. It is still considered active, although no eruptions seem to have occurred within the past 500 years at least, and the volcanic complex shows signs of heavy erosion. Steep valleys and erosion cliffs of up to 1000 m depth cut the base of the older Iyang volcano. The volcano's construction followed a N-S rift-like trend, with overlapping craters and cones forming on this line. At present, there are only fumaroles in Iyang crater as sign of activity. Uncertain reports might indicate an eruption 1597.