|Notes:||Excavated by Callander and Grant in 1936, the Blackhammer stalled cairn is aligned roughly west-east. Measuring 22m long by 8m wide, the structure had survived to a maximum height of 1.5m.|
The sub-rectangular chamber is 13m long, 1.5 to 1.7 m wide but narrowing to 1.2m at the eastern end. Six pairs of divisional orthostats divided the interior into seven compartments and access was by an entrance passage in the southern wall.
The passage, measuring 2.9m long, 0.75 m wide and 1m high, is located slightly east of wall’s centre, meaning it enters the chamber in the third compartment from the east.
Because the passage is at right angles to the chamber, it means that Blackhammer has two end cells, each with a substantial black slab. The excavators found that the entrance passage had been sealed, with the blocking wall flush with the structure’s outer wall.
The masonry on the cairn’s outer face were positioned to form a triangular pattern. Traces of the decorative stonework can still be seen at either side of the entrance and when the entrance was finally sealed, the builders of the blocking wall went to great lengths to ensure it matched the pattern of slanting stones on either side. The blocking’s inner face was left rough.
After the entrance was blocked it seems the chamber was filled with earth and rubble – presumably from above.
At some point before it was sealed, the chamber was modified with two apparent walls inserted across the chamber. The purpose, and date, of these remains unclear.
The occupation layer, below the cairn filling, was found to contain pottery sherds, a stone axe, flint debitage and the fragments of two human skeletons – one in the westernmost compartment and the other in the entrance passage.
In the eastern chamber, animal remains included at least eight adult sheep, cattle, red deer and gannet.
Blackhammer Stalled Cairn, Rousay