Dimmuborgir (Icelandic dark cities or dark castles) is a lava field and the remains of a lava lake east of Lake Mývatn in Iceland. It is located in a volcanically active region in the area of the Krafla volcanic system, directly east of the lake. Adjacent to the northeast is the Tuffring Hverfjall.
The bizarre stone formations of the lava field are reminiscent of the ruined ruins of castles and towers. In Icelandic mythology, Dimmuborgir is seen as the shelter of elves and trolls.