The natural feature associated with volcanic activity in Indonesia is the Pacific Ring of Fire. This area encircles the Pacific Ocean and is famous for its high seismic activity, including numerous earthquakes and volcanoes. Indonesia is home to many active volcanoes, such as Mount Merapi and Mount Krakatoa. The geological activity is primarily caused by tectonic plate movements, which lead to the formation of volcanic islands and rich soil, benefiting agriculture but posing risks to local communities.