A unique megalithic monument on Salisbury Plain in Wiltshire, England. Its alleged connection with the Druids dates from the 17th century, when people’s ideas about what constituted ‘the past’ were very vague. In the 12th century it was believed to be a monument over King Arthur’s grave; other theories have attributed it to the Phoenicians, Romans, Vikings, and visitors from other worlds; modern theory inclines to the view that it was a temple. Scientific study and excavation have identified three main constructional phases between c.3000 bc and c.1500 bc, i.e. it was completed in the Bronze Age. The circular bank and ditch, double circle of ‘bluestones’ (spotted dolerite), and circle of sarsen stones (some with stone lintels), are concentric, and the main axis is aligned on the midsummer sunrise—an orientation that was probably for ritual rather than scientific purposes. It is believed that the ‘bluestones’ were transported from the Prescelly Hills, Pembrokeshire, Wales, a distance of 320 km (200 miles).