The Clava Cairns lie in an open site and you are free to wander among them and even within the two 4,000 year old passage graves. The complex consists of two large passage graves built of rounded stones, a central ring cairn and a kerb cairn, dating from 1,000BC. The passage graves were constructed to align with the rays of the setting sun on the winter solstice; quartz was used to maximise the sun’s effect.