Grjótagjá

Grjótagjá is a lava cave with thermally heated water in the rift zone near Mývatn where the Eurasian and American plates drift apart.

In the 18th century outlaw Jón Markússon used it as a refuge, later locals and tourists bathed in it until the water got too hot during the Krafla Fires (1975-84). After the end of the eruptions the temperature slowly cooled again, but remains unpredictable.

Grjótagjá (Jon Snow's cave) shot to fame with GoT, attracting masses of visitors and vandalism. The private landowners were forced to prohibit bathing in both Grjótagjá and neighbouring Kvennagjá.