The Blackhammer Chambered Cairn, Rousay.

A short distance from Rousay's Taversoe Tuick, and built into a steep slope overlooking Wyre Sound, is the Blackhammer stalled cairn.

Thought to date from around 3,000 BC, the structure is a typical stalled cairn, with an interior divided into seven compartments by pairs of upright stone slabs.

Today, a modern roof covers the original remains of the cairn, which are are only a few feet high. Windows built into this concrete construction supply ample light to explore the site.

Stonework from the Blackhammer Cairn	Corresponding pattern from an Unstan ware pot

The original entrance was sealed up when the cairn was abandoned, so modern access to the interior is through a hatchway in the roof and ladder.

The structure is a 13-metre long oblong and was originally constructed with a distinct decorative design incorporated into its outer facing.

The stone slabs on the outside of the cairn were slanted to form a triangular pattern in the stonework. It is interesting to note the similarity between this pattern and the patterns scratched into the rims of Unstan ware pottery.

Traces of the decorative stonework can still be seen at either side of the entrance and when the entrance was finally sealed, the cairn's users went to great lengths to ensure the stones used were set flush to the wall and matched the pattern of slanting stones on either side.

The western end of the Blackhammer chambered tomb.

The Blackhammer Cairn was excavated in 1936, with the remains of two men found inside. One body was in the most westerly compartment, the other lying in the entrance passage.

The fact that the cairn only contained the remains of two people seems to imply that the chambers were regularly cleared out - the remains of the recently dead replacing those of previous generations.

Among the other finds were animal bones, stone and flint tools, the remains of an Unstan-style bowl and a burnt flint knife.

Among the other bones scattered throughout the cairn were those of sheep, ox, red deer, geese, red deer, gannets and cormorants. Many of these bones showed signs of burning or scorching.

Other finds included a section of an Unstan ware urn, a finely-made flint knife, two scrapers and five flint splinters.