Stonehenge survey. Surveyors at Stonehenge in the 1860s. This view shows trilithons B and C, seen from the south-west. Stonehenge is a prehistoric circle of standing stones located in Wiltshire, UK. It dates from 3000 BC to 2000 BC, with different construction phases in that period. Theories about its function range from astronomical observatory to religious site. This photograph is from 'Plans and Photographs of Stonehenge, and of Turusachan in the Island of Lewis' (1867). The photographs were taken by the Ordnance Survey Department, led by Sir Henry James (at left, 1803-1877).