Stonehenge is a world-renowned prehistoric monument located in the English county of Wiltshire.
One of the most famous prehistoric sites in the world, Stonehenge is composed of earthworks surrounding a circular setting of large standing stones. Archaeologists believe that the standing stones were erected around 2200 BC and the surrounding circular earth bank and ditch, which constitute the earliest phase of the monument, have been dated to about 3100 BC.
Each standing stone is around 4.1 metres (13 ft) high, 2.1 metres (6.9 ft) wide and weighed around 25 tons. Each had clearly been worked with the final effect in mind; the orthostats widen slightly towards the top in order that their perspective remains constant as they rise up from the ground while the lintel stones curve slightly to continue the circular appearance of the earlier monument. (Wiki)
This picture almost got me arrested!