The Tankerness peninsula is underlain by Rousay flagstones, an Old Red Sandstone of Middle Devonian age, that were deposited in Lake Orcadie.

[4][5] These lacustrine rocks were laid down when the land that now forms Orkney was 16 degrees south of the equator within the Southern Hemisphere's desert belt.

[7][8] Mine Howe, at Toab in the south of Tankerness, is a prehistoric subterranean man-made chamber dug into a large mound.

Its walls are lined with stones fitted to form an arch over the cavity and 29 steps lead to a rock floor.

The origin of the howe (from Old Norse word haugr meaning barrow) is not perfectly understood, although it is thought to date from the Iron Age.

A variety of concrete buildings remain, including those that housed two six-inch guns salvaged from the battleship HMS Iron Duke.

In 1960s 50-100 geese were regularly found there in the winter but there has been a sharp decline in numbers since 1974/75 probably as a result of reclamation of moorland and an increase in shooting in the area.