Grjótagjá is a small cave that hides a hot spring
Grjótagjá is a small lava cave with a thermal spring inside, near the lake Mývatn, in north Iceland. It was a popular bathing spot for locals, until the eruptions in the late 70’s. Grjótagjá is a Game of Thrones filming location. It is now a private property and it is forbidden to bathe in it.