There were three main building phases, each between about 3100 BC and 1950 BC. The first circle, ~3000 BC, was made of timber. The post holes for the timber have been found. Around 2600 BC, the builders gave up timber in favour of stone. Most of the construction took place between 2640 and 2480 BC.
The first stone circle was a set of 'bluestones'. The holes held up to 80 standing stones (shown blue on the plan), only 43 of which can be traced today. The bluestones (made of dolerite, an igneous rock), were thought for much of the 20th century to have been brought from the Preseli Hills, 160 miles (260 kilometres) away in modern-day Pembrokeshire, Wales. Another theory is that they were brought much nearer to the site as glacial erratics by the Irish Sea Glacier.
Later, ~2400 BC, 30 huge grey sarsen stones were brought to the site. They were erected in a circle 33 metres in diameter, with lintels on top of the standing stones. The remaining blue circles were placed as an inner circle. The site was in use until the Bronze Age. The modern Stonehenge consists entirely of original stones, some of which have been replaced in upright position.
No one knows who built Stonehenge or why they built it. During the summer solstice, the sunrise lines up with some of the stones in a particular way. This suggests that the arrangement of stones may work as a calendar. In Egypt and South America, similar ancient buildings can be found. They also show the time of the solstice.
The World Heritage Site includes Avebury and Stonhenge together, though they are quite distinct sites. Stonehenge, however, does have a number of satellite structures which are part of the 'ritual landscape':
- Bluehenge/Bluestonehenge: a new discovery, one mile to the southeast.
- Durrington Walls: a Neolithic settlement two miles northeast of Stonehenge.
- Normanton Down Barrows: a Neolithic and Bronze Age barrow cemetery.
- Stonehenge Avenue: leads two miles from Stonehenge to Bluehenge on the River Avon.
- Stonehenge Cursus: the largest monument in the area, not easily visible on the ground.
- Woodhenge: found in 1925 by an aerial survey. It had a henge and a wooden circle.
- UNESCO, "Stonehenge, Avebury and Associated Sites"; retrieved 2012-4-19.
- Remains of a former ring bank and ditch
- Marc Kaufman (January 31, 2007). "An ancient settlement is unearthed near Stonehenge". The Washington Post. https://www.washingtonpost.com/wp-dyn/content/article/2007/01/30/AR2007013000661.html. Retrieved 2008-05-23.
- John, Brian 2007: The Stonehenge Bluestones—glacial transport back in favour
- "How did Stonehenge come into the care of English Heritage?". FAQs on Stonehenge. English Heritage. http://www.english-heritage.org.uk/server/show/conWebDoc.4189. Retrieved 2007-12-17.
- "Ancient ceremonial landscape of great archaeological and wildlife interest". Stonehenge Landscape. National Trust. http://www.nationaltrust.org.uk/stonehengelandscape. Retrieved 2007-12-17.