The ochre crater of Víti reveals a secret when you reach its rim – a cerulean pool of floodwater at its heart. The 300m-wide explosion crater was created in 1724 at the beginning of the destructive Mývatn Fires. There is a circular path from the car park around the rim.
Note: don't confuse this Víti crater with the Víti crater beside the Askja caldera (you can bathe inside the latter, but not the former). Fun fact: Víti means 'hell' in Icelandic.