about 6 miles (10 km) from skara brae, grooved ware pottery was found at the standing stones of stenness (originally a circle) which lie centrally in a close group of three major monuments. maeshowe, the finest example of the passage grave type of chambered cairn (radiocarbon dated to before 2700 bc) lies just to the east. the ring of brodgar circle of standing stones is across a bridge immediately to the north. this circle was one of the first to be analysed by professor alexander thom to establish the likely use of standing stones as astronomical observatories. another neolithic village has been found nearby at barnhouse settlement, and the inference is that these farming people were the builders and users of these mysterious structures.