The Rennibister earth-house
Located in the yard of a working farm, by the south-eastern shore of Bay o' Firth, the Rennibister earth-house is certainly the most picturesque of the two Orkney earth-houses accessible to the public today.
The underground structure was discovered in November 1926, when a section of the roof collapsed under the weight of a threshing machine passing through the gate to the farm's stackyard.
Like the Grain earth-house, Rennibister is thought to date from the first millennium BC.
Access was originally made via an 11.5 feet (3.5 metres) long, low entrance passage that led to a 2.5 feet (76cm) drop to the main chamber. There were no steps into the passage, so it is thought the visitor dropped through hole into the passage.
Measuring only 2.3 feet (70 cm) high by 2.3 feet (70 cm) wide, gaining entry to the lower chamber would never have been particularly easy. Today, however, the visitor enters via a hatch in the roof that leads into the chamber.
Inside, the drystone walls of the main chamber - measuring approximately 11ft (3.35m) by 8.5ft (2.6m) at maximum - curve upwards to a corbelled roof measuring 5ft (1.5m) at its highest. As at Grain, four stone pillars support the roof’s weight, but Rennibister is different because it has five small stone alcoves built into the walls of the chamber.
When excavated, the passage to the Rennibister chamber was found to be "choked" with a deposit of earth mixed with "vast" quantities of shells.
The chamber was free of this deposit, but was found to contain the remains of six adults and 12 children. This significance of this discovery remains unclear today. The Rennibister bones were disarticulated, which shows that the corpses were already fleshless when deposited in the chamber.
The archaeological experts declared that the structure was not originally designed as a burial vault, which would imply the chamber used to inter the bodies later in is life, or pehaps even after it went out of use.
For years Rennibister was claimed to be the only Orcadian earth-house, found to contain obvious human remains - but recent excavations at Windwick in South Ronaldsay revealed large quantities of cremated bone.
In addition, investigations by archaeologist Martin Carruthers have shown that a number of others did actually contain remains, and even Rennibister’s “haphazard” inhumation was not as random as most now believe.