Italy
Mount Sempu is a volcano in the northern arm of Sulawesi, Indonesia, which contains a 3 km wide caldera. A maar, called Kawah Masem, was formed in the south-west of the caldera and contains a crater lake. Sulfur deposits have been extracted from the maar since 1938. Historical records, however, are
unknown from the volcano.
Listen to the audio guide for Mount Sempu Free on WIP — starts by itself when you arrive, even with the screen off