Indonesia (i/ˌɪndəˈniːʒə/ IN-də-NEE-zhə or /ˌɪndoʊˈniːziə/ IN-doh-NEE-zee-ə), officially the Republic of Indonesia (Indonesian: Republik Indonesia Indonesian pronunciation: [rɛpʊblik ɪndonesia]), is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 17,508 islands. It has 34 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an elected legislature and president. The nation's capital city is Jakarta. The country shares land borders with Papua New Guinea, East Timor, and Malaysia. Other neighboring countries include Singapore, Philippines, Australia, Palau, and the Indian territory of the Andaman and Nicobar Islands. Indonesia is a founding member of ASEAN and a member of the G-20 major economies. The Indonesian economy is the world's sixteenth largest by nominal GDP and fifteenth largest by purchasing power parity.
The geography of Indonesia is dominated by volcanoes that are formed due to subduction zones between the Eurasian plate and the Indo-Australian plate. Some of the volcanoes are notable for their eruptions, for instance, Krakatau for its global effects in 1883, Lake Toba for its supervolcanic eruption estimated to have occurred 74,000 years before present which was responsible for six years of volcanic winter, and Mount Tambora for the most violent eruption in recorded history in 1815.
Volcanoes in Indonesia are part of the Pacific Ring of Fire. The 150 entries in the list below are grouped into six geographical regions, four of which belong to the volcanoes of the Sunda Arc trench system. The remaining two groups are volcanoes of Halmahera, including its surrounding volcanic islands, and volcanoes of Sulawesi and the Sangihe Islands. The latter group is in one volcanic arc together with the Philippine volcanoes.