Rennibister Earth House is a small, unsettling counterpoint to Orkney's grander prehistoric monuments. You descend by ladder into a stone-lined underground chamber, the kind of Iron Age souterrain that feels more like a secret than a showpiece.
Its power comes from the discovery story. When the site was exposed in 1926, the chamber floor held the bones of several adults and children, apparently placed there after the original use of the earth house had changed. It is close enough to Kirkwall to combine with other Mainland Orkney sites, but it feels much more intimate than the headline stops.