This point, close to the Heel Stone, lies on the axis of Stonehenge. This is an alignment that runs north-east to south-west, up the final straight section of the Avenue and through the enclosure entrance. Recent excavations have shown that this part of the Avenue may be based on natural landscape features – “visible stripes” in the surface of the chalk formed at the end of the last Ice Age.
Within the central stones the alignment runs through the open ends of the horseshoes of sarsen and bluestone to where the Altar Stone lies at the base of the Great Trilithon.
This axis was carefully chosen because it reflects the annual movements of the sun. At Stonehenge on the longest day of the year, about 21 June in the modern calendar; the sun rises behind the Heel Stone in the north-east part of the horizon and its first rays shine into the heart of Stonehenge. This alignment is deliberate; it is shared with many other henges – temples of earth and wood – that were built around the same time. Close to Stonehenge there are two good examples, Coneybury to the south-east and Woodhenge to the north-east. The careful way that Stonehenge is laid out is seen as evidence that it was designed to mark and, presumably, celebrate the middle point of summer – the summer solstice. But an alignment that marks a midsummer event in one direction can also point to a midwinter event.
Because of the way the sun moves through the sky during the course of the year, the sunset at the winter solstice, the shortest day of the year, occurs on exactly the opposite side of the horizon from the midsummer sunrise. Observers at Stonehenge at the winter solstice (about 21 December), standing in the enclosure entrance and facing the centre of the stones, can watch the sun set in the south-west part of the horizon, just to one side of the only remaining upright of the Great Trilithon.
When this magnificent structure stood intact this effect would have been dramatic, the setting sun dropping rapidly down the narrow gap between the two upright stones. So Stonehenge may have been built to commemorate not so much the longest day, the summer solstice, but the shortest day, the solstice in the depths of winter. But why?
Within the central stones the alignment runs through the open ends of the horseshoes of sarsen and bluestone to where the Altar Stone lies at the base of the Great Trilithon.
Stonehenge at midsummer sunset.
This axis was carefully chosen because it reflects the annual movements of the sun. At Stonehenge on the longest day of the year, about 21 June in the modern calendar; the sun rises behind the Heel Stone in the north-east part of the horizon and its first rays shine into the heart of Stonehenge. This alignment is deliberate; it is shared with many other henges – temples of earth and wood – that were built around the same time. Close to Stonehenge there are two good examples, Coneybury to the south-east and Woodhenge to the north-east. The careful way that Stonehenge is laid out is seen as evidence that it was designed to mark and, presumably, celebrate the middle point of summer – the summer solstice. But an alignment that marks a midsummer event in one direction can also point to a midwinter event.
The Heel Stone, one of two sarsens that once stood just outside the main entrance to the enclosure, framed by the outer sarsen circle.
Because of the way the sun moves through the sky during the course of the year, the sunset at the winter solstice, the shortest day of the year, occurs on exactly the opposite side of the horizon from the midsummer sunrise. Observers at Stonehenge at the winter solstice (about 21 December), standing in the enclosure entrance and facing the centre of the stones, can watch the sun set in the south-west part of the horizon, just to one side of the only remaining upright of the Great Trilithon.
When this magnificent structure stood intact this effect would have been dramatic, the setting sun dropping rapidly down the narrow gap between the two upright stones. So Stonehenge may have been built to commemorate not so much the longest day, the summer solstice, but the shortest day, the solstice in the depths of winter. But why?