Volcanoes are as dangerous as they are majestic. Over 50 eruptions rock our planet every year. This video helps you understand what causes volcanoes to form and erupt—and shows where they are most likely to be found. | National Geographic TV

Portals into the machinations of the Earth, volcanoes take many forms – and occur due to a range of underlying processes. Take a look at these spectacular examples to understand a little about their destructive power – and the reason why | National Geographic UK