Part of Avebury Stone Circle in Avebury, Wiltshire, England; the stones date back to around 2500 BC, the same time as nearby Stonehenge; Avebury contains the largest stone circle in Europe, and within that circle are two smaller circles; there are over 100 remaining stones; Avebury is 16 times larger than Stonehenge
Standing stones at Pentre Ifan in Pembrokeshire, Wales. This Bronze Age monument, also known as Arthur's Quoit, dates from around 4000-3500 BC. It is thought to have been constructed as a burial chamber and would have originally been covered in earth. The capstone of the chamber is about 5 metres long. Photographed in Pembrokeshire Coast National Park, Wales.