The Clava cairn is a type of Bronze Age circular chamber tomb cairn, named after the group of 3 cairns at Balnuaran of Clava, to the east of Inverness. There are about 50 cairns of this type in an area round about Inverness.
At Balnuaran of Clava itself there is a group of three Bronze Age cairns which lie close together in a line running north east to south west. The tombs at either end are of the passage grave sub-type. The central cairn is of the ring cairn sub-type, and uniquely has stone paths or causeways forming 'rays' radiating out from the platform round the kerbs to three of the standing stones. The cairns incorporate cup and ring mark stones, carved before they were built into the structures. The kerb stones are graded in size and selected for colour, so that the stones are larger and redder to the south west, and smaller and whiter to the north east. All these elements seem to have been constructed as one operation and indicate a complex design rather than ad hoc additions.
The ring round the northern Balnuaran of Clava cairn was measured and analysed by Professor Alexander Thom. He found that the ring was slightly egg-shaped with a complex geometry of circles and ellipses which could be set out around a central triangle, using sizes which are close to whole multiples of what he called the Megalithic yard. While the geometry of the shape is generally accepted, the Megalithic Yard is more controversial.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.