Stonehenge is one of the most prominent prehistoric monuments in Britain. Stonehenge that can be seen today is the last stage that was completed about 3,500 years ago.
According to the memorial’s website, Stonehenge was built in four phases:
The first stage: The first version of Stonehenge was a large earthwork or Henge, consisting of a moat, bank and Aubrey holes, all probably built around 3100 BC.
Aubrey’s holes are round pits in chalk, about a meter (3.3 ft) wide and deep, with steep sides and flat bottoms.
Stonehenge (pictured) is one of the most prominent prehistoric monuments in Britain
It forms a circle with a diameter of about 86.6 meters (284 feet).
Excavations have revealed burnt human bones in some chalk filling, but it is likely that the holes themselves were not made to be used as tombs, but as part of a religious ceremony.
After this first stage, Stonehenge was abandoned and untouched for over 1,000 years.
The second phase: The second and most dramatic phase of Stonehenge began around 2150 BC, when about 82 bluestones were moved from the Presley Mountains in southwest Wales to the site. The stones, some weighing four tons each, are believed to have been towed on rollers and sleds into the water at Milford Haven, where they were loaded onto rafts.
They were carried on water along the south coast of Wales and up to the Avon and Frome rivers, before being towed overland again near Warminster and Wiltshire.
The final leg of the journey was mainly by water, down the Willy River to Salisbury, then Salisbury Avon to West Amesbury.
The journey spanned nearly 240 miles, and once at the site, stones were set in the center to form an incomplete double circle.
During the same period, the original entrance was enlarged and two pairs of heel stones erected. The part closest to the avenue, which connects Stonehenge to the River Avon, is built parallel to the midsummer sunrise.
third level: The third phase of Stonehenge, which occurred around 2000 B.C., saw the arrival of the Sarcin (a type of sandstone), which were larger than the blue stones.
They were likely brought from Marlborough Downs (40 kilometers, or 25 miles, north of Stonehenge).
The largest sarsen stones transported to Stonehenge weighed 50 tons, and transport by water was not possible, so it is suspected that they were transported using sleds and ropes.
Calculations showed that pulling a single stone would have taken 500 men using leather ropes, plus an additional 100 men to put the pulleys in front of the sled.
These stones are arranged in an outer circle with a continuous series of lintels – horizontal buttresses.
Within the circle, five trilithons – structures consisting of two erect stones and a third across the top as a lintel – are set in a horseshoe arrangement, which can still be seen to this day.
Final stage: The fourth and final stage occurred just after 1500 BC, when the smaller blue stones were rearranged into the horseshoe and circle that can be seen today.
The original number of stones in the bluestone circle was probably about 60, but they have since been removed or broken apart. Some still like tree trunks below ground level.