Stonehenge is a prehistoric monument and one of the most famous tourist attractions in the world, located in Wiltshire, England. The site consists of a circular setting of large stones, known as megaliths, surrounded by earthworks that form a ceremonial enclosure. The largest stones, known as the sarsens, weigh around 50 tons and are up to 30 feet tall, while the smaller stones, known as the bluestones, weigh around 4 tons and are up to 6 feet tall. The stones are arranged in a pattern of concentric circles, with the largest stones forming the outer circle and the smallest stones forming the inner circle. The site also features earthworks, including a circular bank and ditch, and several burial mounds. Stonehenge is believed to have been built in several stages between 3000 and 1500 BCE, and its purpose is still shrouded in mystery, with theories ranging from an astronomical observatory to a place of healing and spiritual ritual.