How many active volcanoes does Indonesia have ?
The longest currently ongoing ( but not necessarily continuous ) volcanic eruptive phases are : Mount Yasur , 111 years Mount Etna , 109 years Stromboli , 108 years Santa María , 101 years Sangay , 94 years Other very active volcanoes include : Mount Nyiragongo and its neighbor , Nyamuragira , are Africa 's most active volcanoes .