England - Aerial view of Stonehenge,. Wiltshire. A megalithic monument, dating back to around 3000 BC, when a ring of pits was dug inside a circular earthwork. A single entrance faced north-east and near here a rough monolith, the heel stone, was erected. Almost a thousand years later, huge stones were hauled from the Prescelly Mountains in South Wales, and erected with great accuracy to create a Neolithic calendar, which could predict the seasons, moon cycles and eclipses.The monument also serv