The bluestones at Stonehenge were placed there during the third phase of construction at Stonehenge around 2300 BC. The stones weigh between 2 and 4 tons each. The majority of them are believed to have been brought from the Preseli Hills, about 250 miles away in Wales!
The “henge” portion has given its name to a class of monuments known as henges. Archaeologists define henges as earthworks consisting of a circular banked enclosure with an internal ditch.
The site and its surroundings were added to the UNESCO’s list of World Heritage Sites in 1986.