As the path continues around the perimeter of the enclosure, it passes a small sarsen stone close to the inner edge of the bank. This is one of four known as the Station Stones that originally stood on roughly the same line as the Aubrey Holes.

As the path leads back over the bank and ditch, note the pale concrete spots in the grass that mark the position of excavated Aubrey Holes. The path then curves left round the outside of the enclosure.

Moving further along the path parallel with the central stones, visitors get a clear view of the way in which the larger sarsens have been shaped and fitted together. At most stone circles built at this time in prehistory, blocks of stone were left in their natural, rough state and simply raised upright, but at Stonehenge they were treated differently. The sarsens within the central settings have been carefully trimmed, sometimes to produce sharply defined rectangular blocks, and have also been shaped to produce simple joints that lock the stones tightly together.

In the form of its ditch and the animal bones that were carefully placed there, the first Stonehenge was not so different from many other enclosures of a similar date. Even cremated human bones have been found at other sites of this date. What made Stonehenge so unusual is what happened next: the arrival of the stones.

The tunnel from the visitor centre emerges a little distance from the stones, outside the boundary formed by the circular ditch and bank. These earthworks are now grassed over, but are clearly visible as the path crosses over them on its way to the inner part of the monument. This is the first Stonehenge, constructed shortly after 3000 BC in the period known as the Neolithic or New Stone Age. In this, its first form, Stonehenge was similar to a number of other sites known as causewayed enclosures. Another example, Robin Hood’s Ball, lies about a mile to the north-west.

Radiocarbon dating measures the amount of radioactive carbon in an archaeological sample. When calibrated against the radiocarbon content of tree rings with a known age, this can give very precise dates.

Stonehenge sits within a triangle of land bordered on two sides by busy roads. To the south is the A303, the main route from London to the South West. To the north lies the A304, which runs right past Stonehenge and cuts the main temple off from its landscape setting. This situation is not ideal, and there are plans for great improvements.

Stonehenge – Britain’s greatest ancient temple, dating from about 3000 to 1600 BC.Today, visitors experience Stonehenge as a wonder of ancient achievement and an enduring symbol of mystery. But Stonehenge was built as a temple – a place of ceremony, of burial and of celebration. The first Stonehenge was simple – just a circular ditch and bank – and was constructed about 5000 years ago, in the period of prehistory known as the Neolithic or New Stone Age.

The old Saxon word ley (also spelt lea, lee or leigh) was defined in the Oxford English Dictionary as “Land temporarily under grass” and particularly refers to an enclosed field or pasture.

Stonehenge is at the heart of a sacred and a ritual landscape, surrounded by the graves of the elite of prehistory. If the stone circle can be seen as the hub of a wheel, there are solar and lunar alignments which go through the centre like the spokes of a wheel. The kind of alignments found at Stonehenge are the kind that would have been the result of prolonged observation rather than mathematical precision, as has sometimes been suggested.