Grjotagja

A Lava Cave Born From Fire

Grjotagja is a small lava cave located on the eastern shore of Lake Myvatn in North Iceland. It was formed by volcanic activity along a fissure in the Earth's crust, part of the larger Krafla fissure zone that extends roughly 90 kilometers through this region. As lava flowed beneath the surface, the outer layer cooled and hardened while molten rock continued to move underneath, eventually draining away and leaving behind the hollow passage that exists today. Inside the cave, geothermally heated groundwater fills a natural pool with strikingly clear, turquoise-blue water.

History and the Outlaw of Myvatn

Grjotagja has been known to Icelanders for centuries. In the early 18th century, the outlaw Jon Markusson used the cave as a hiding place and bathed in its warm waters. For much of the 20th century, locals treated it as a natural hot spring, and bathing here was a beloved tradition in the Myvatn community.

That changed in 1975 when the Krafla volcanic system began a series of eruptions that would last until 1984, known as the Krafla Fires. These nine eruptions dramatically increased the water temperature in Grjotagja, pushing it well above 50 degrees Celsius and at times close to boiling. Bathing became impossible and has been prohibited ever since. While the water has cooled somewhat in the decades since, temperatures remain unpredictable and unsafe, typically fluctuating between 40 and 50 degrees Celsius.

Game of Thrones Fame

Grjotagja gained international recognition when it became associated with HBO's Game of Thrones. The cave inspired the setting for the scene in Season 3, Episode 5 where Jon Snow and Ygritte share an intimate moment in a hot spring cave beyond the Wall. While the actual scene was filmed on a studio set rather than in the cave itself, the production team closely recreated the look of Grjotagja, and the association brought a surge of visitors to this once-quiet spot. The nearby Dimmuborgir lava formations also served as a filming location for the wildling camp scenes.

Visiting Grjotagja

The cave is easy to reach from Reykjahlid, the main service village at Lake Myvatn. A short drive east on Route 1 followed by a turn onto gravel road 860 brings you to a small parking area. From there, a brief walk leads to the cave entrance. The terrain is uneven lava rock, so sturdy footwear is recommended, but no special equipment or fitness level is needed.

Inside, you can look down into the pool from a rocky ledge. The water glows an ethereal blue-green in the dim light filtering through cracks in the lava roof. It is a genuinely beautiful sight that takes only a few minutes to appreciate but tends to stay in the memory. The cave sits on private land, and the landowners have closed access temporarily in the past when visitor behavior caused damage. Stay on established paths, do not enter the water, and leave nothing behind.

Part of a Bigger Picture

Grjotagja works best as one stop on a day spent exploring the Lake Myvatn area. The Krafla volcanic zone, Namafjall geothermal field with its bubbling mud pots, Hverfjall tephra crater, and the strange lava pillars of Dimmuborgir are all within a short drive. If you want to actually soak in geothermal water, the Myvatn Nature Baths offer a legal and comfortable alternative just a few kilometers away.