At 200ft by 250ft, this is the world’s second-largest boiling lake: the first is Frying Pan Lake, on New Zealand’s North Island, which fills a volcanic crater and is less agitated at about 55C.

It sounds amazing, and it is. The Boiling Lake is a fumarole, or an opening in the Earth's crust that releases steam and gas, and it's flooded with hot bubbling water that rises into a cloud of vapor.