Game of Thrones fans may recognise it as the place where John Snow is deflowered by Ygritte. Grjótagjá is a gaping fissure with a 45°C water-filled cave. It's on private property – it's prohibited to bathe here, but the owners allow the public to visit and photograph. It’s a beautiful spot, particularly when the sun filters through the cracks in the roof and illuminates the interior.
