How Was Stonehenge Built?
Stonehenge was constructed over six stages between 3000 and 1520 bce using a sophisticated post-and-lintel system, with massive stones transported from distant locations and arranged in a precise circular formation. The initial phase of the construction of Stonehenge (located on Salisbury Plain, England) began with the creation of a circular enclosure more than 330 feet (100 meters) in diameter. This enclosure included 56 pits known as the Aubrey Holes, which likely held Welsh bluestones. These stones were transported from the Preseli Mountains in southwest Wales, a journey of over 140 miles (225 km), possibly by human effort or glacial movement. The site also featured a ditch flanked by an inner high bank and an outer low bank, with entrances on the northeast and south, setting the stage for the monument’s future development.
About 2500 bce the construction of Stonehenge’s iconic sarsen stones began. These stones, sourced from the Marlborough Downs about 20 miles (32 km) away, were meticulously smoothed and arranged inside the circle in a horseshoe formation of five trilithons (paired uprights with a lintel), which stood up to 32 feet (10 meters) high and weighed more than 45 tons. These were surrounded by a circle of 30 uprights linked by curved lintels. The lintels are held on top of the uprights by mortise-and-tenon (dovetail) joints, and the ends of the curved lintels of the sarsen circle are fitted together with tongue-and-groove joints.
The bluestones, weighing up to 4 tons each, were arranged in a double arc known as the Q and R Holes, possibly as part of the sarsen circle and trilithon monument. An avenue (built between 2470 and 2280 bce) leading to the River Avon is aligned with the summer solstice sunrise and winter solstice sunset. This alignment, along with the monument’s construction, suggests Stonehenge’s use as an astronomical observatory and indicates a deep understanding of celestial events by its builders.
About 2200 bce the bluestones were rearranged to form a circle and an inner oval. Two rings of pits were built in the final stages of construction. The first ring of pits, known as the Z Holes, was built between 2030 and 1750 bce; the second ring of pits, known as the Y Holes, were built between 1640 and 1520 bce.