Which country has the largest number of active volcanoes?

Indonesia has the largest number of active volcanoes of any country.

Indonesia lies along the Pacific Ring of Fire, where several tectonic plates meet and the Indo-Australian Plate is forced beneath parts of the Eurasian and other plates. This subduction generates magma and creates the long volcanic arcs running through Sumatra, Java, Bali, the Lesser Sunda Islands, Sulawesi, and the Moluccas.

Indonesia is commonly listed with about 127 active volcanoes, although counts vary because scientists use different definitions of “active.” A volcano may be classified by a documented historical eruption, evidence of activity during the Holocene, or continuing geothermal and seismic signals. The U.S. Geological Survey has counted 75 historically active Indonesian volcanoes under a narrower definition.

Mount Merapi is Indonesia’s most active volcano and has erupted repeatedly since 1548. Krakatau, Tambora, and Toba are also famous Indonesian volcanic systems. The country’s volcanic soils support agriculture, but eruptions, ash, lava, and lahars pose serious risks to densely populated communities.