About 1,500 active volcanoes can be found around the world. Learn about the major types of volcanoes, the geological process behind eruptions, and where the most destructive volcanic eruption ever witnessed occurred. Subscribe: http://bit.ly/NatGeoSubscribe #NationalGeographic #Volcanoes #Educational About National Geographic: National Geographic is the world's premium destination for science, exploration, and adventure. Through their world-class scientists, photographers, journalists, and filmmakers, Nat Geo gets you closer to the stories that matter and past the edge of what's possible.