The Keldur farm estate in southern Iceland features a number of crude sod structures that are found nowhere else in the region, but the most remarkable is likely the public hall which features a number of rooms and even a hidden escape tunnel built into the hill.

Consisting of over 20 turf structures that are still standing, the Keldur farm has existed for almost a thousand years. The location is featured prominently in the historic Njal's Saga, which states that the location was founded in the year 1,000 CE, although current estimates place the settlement as much older. Keldur Hall is believed to have been built during the 11th-century, however, which would make it the oldest hall of its kind in all of Iceland. The hall was likely inhabited by Jon Loftsson, a strongly religious chieftain from the 12th century.

The site has been added to, preserved, and generally cared for over its centuries of existence, but it was not until 1932 that the most remarkable feature was discovered. Set into the floor, where it is said that it would have been beneath a throne of some sort, is the entrance to a skinny escape tunnel. The crude emergency tunnel leads down and into the hill behind the hall, allowing one to flee to the opposite base of the hill. The opening is quite small, so it is unknown how effective it would have been.

Keldur Hall and the surrounding farm are now under the purview of the National Museum of Iceland, and visitors can check out the escape hole, but it is grated over, so a quick getaway might be a bit more challenging.