what is Stonehenge ?

Stonehenge is a prehistoric monument located in the English county of Wiltshire, about 3.2 kilometres (2.0 mi) west of Amesbury and 13 kilometres (8.1 mi) north of Salisbury. One of the most famous sites in the world, Stonehenge is composed of earthworks surrounding a circular setting of large standing stones and sits at the centre of the densest complex of Neolithic and Bronze Age monuments in England, including several hundred burial mounds. Archaeologists had believed that the iconic stone monument was erected around 2500 BC, as described in the chronology below. However one recent theory has suggested that the first stones were not erected until 2400-2200 BC, whilst another suggests that bluestones may have been erected at the site as early as 3000 BC (see phase 1 below). The surrounding circular earth bank and ditch, which constitute the earliest phase of the monument, have been dated to about 3100 BC. The site and its surroundings were added to the UNESCO's list of World Heritage Sites in 1986 in a co-listing with Avebury henge monument, and it is also a legally protected Scheduled Ancient Monument. Stonehenge itself is owned by the Crown and managed by English Heritage while the surrounding land is owned by the National Trust

Stonehenge is a megalithic rock monument of 150 enormous stones set in a purposeful circular pattern, located on the Salisbury Plain of southern England, the main portion of it built about 2000 BC. The outside circle of Stonehenge includes 17 enormous upright trimmed stones of hard sandstone called sarsen; some paired with a lintel over the top. This circle is about 30 meters (100 feet) in diameter, and, stands about 5 meters (16 feet) tall.

Inside the circle are five more paired-and-linteled stones of sarsen, called trilithons, each of these weighing 50-60 tons and the tallest 7 meters (23 feet) high. Inside that, a few smaller stones of bluestone, quarried 200 kilometers away in the Preseli Mountains of western Wales, are set in two horseshoe patterns. Finally, one large block of Welsh sandstone marks the center of the monument.

Stonehenge is a several millennia-old prehistoric monument of mysterious origin located on the Salisbury Plain in southern England. Consisting of a circle of large standing stones, many weighing 30 tons or more, Stonehenge is today a UNESCO World Heritage Site.