Some 5,000 years ago, the prehistoric people of the Orkney Islands began building extraordinary monuments out of stone. Each of the four Heart of Neolithic Orkney sites is a masterpiece of Neolithic design and construction in itself. But together they represent one of the richest surviving Neolithic landscapes in Western Europe. The series of important domestic and ritual monuments gives us incredible insights into the society, skills and spiritual beliefs of the people who built the monuments. The Ring of Brodgar is a great stone circle 130m across. Surrounded by a rock cut ditch, it is set in a spectacular natural amphitheatre of lochs and hills.