Grjótagjá Canyon
Located in North East Iceland, by Lake Mývatn. A small cave with a geothermal hot spring. It used to be a popular bathing place with an ideal temperature of around 40 degrees C, but geological activity from 1975-1984 caused the temperature of the water to rise to 50 degrees C, making bathing impossible. Even if bathing it is not allowed, one can dip in a finger, with caution, to feel the water. In the third season of the HBO Series Game of the Thrones, season three, one of the scenes is filmed in Grjótagjá cave.
GPS: 65.627098, -16.881479Parking lot GPS: 65.626145, -16.882380