Grain Earth House is a small Iron Age souterrain on the edge of Kirkwall, easy to miss and surprisingly memorable once you know what it is. A low passage leads to an underground chamber built with stone slabs, probably used for storage or ritual in a much older Orcadian landscape.
It is not a grand monument like Maeshowe, but that contrast is useful. Grain shows the intimate, practical scale of prehistoric life, and its proximity to town makes it a simple stop for anyone with a serious interest in Orkney archaeology.