Kirkjan Cave

Located among the bizarre lava formations of Dimmuborgir (Dark Castles) in the Lake Myvatn area, the unique Kirkjan (the Church) formations resemble the interior of a Gothic cathedral with a three meter (16 ft) hole running through it.

Dimmuborgir is a large area of unusually shaped lava fields east of Mývatn in Iceland. The Dimmuborgir area is composed of various volcanic caves and rock formations, reminiscent of an ancient collapsed citadel (hence the name). The dramatic structures are one of Iceland's most popular natural tourist attractions.

Kirkjan or the Church is a large lavatube strutcture at Dimmuborgir, one that strongly reminds of medieval Gothic cathedrals. 

In Icelandic folklore, Dimmuborgir is said to connect earth with the infernal regions. In Nordic Christian lore, it is also said that Dimmuborgir is the place where Satan landed when he was cast from the heavens and created the apparent "Helvetes katakomber" which is Norwegian for "The Catacombs of Hell".