Iceland is famous for its geysers, but how do they really work?
We walk on it every day but most of us don't think about what's going on in the ground beneath our feet. In Iceland it's hard to ignore.
BBC Earth visits Iceland where Melissa Hogenboom explains how as intense pressure builds up, it can cause heated water to escape out the ground.
Filmed and edited by Pierangelo Pirak.
Read more: The cracks ripping Earth apart
Watch: We went troll hunting in Iceland
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