Volcanoes

Wikimedia Commons has media related to Volcanoes.

Volcanoes are usually mountains (sometimes islands, lakes, plateaus, calderas, seamounts or lava domes) that are formed when magma (liquid rock) wells up from inside the Earth. There are also analogous formations away from the Earth.

Many volcanoes are categorized both as volcanoes and other landforms, such as mountains (if qualified).