Situated on the vast Salisbury plain surrounded by hundreds of barrows, Stonehenge evokes wonder and magic as you approach it. But, Stonehenge today is a monument in ruin. Centuries of damage from natural and manmade causes have left a shell of the former majesty of this great structure. A major roadway runs within a hundred yards and the lure of the site's magic has created a tourist mecca that somehow still can not destroy a visitor's wonder. Close visitor contact has been prohibited since 1978; necessary for its good, for one can not help but feel drawn to approach and touch the mighty trilithons expecting the shock of recognition and spiritual renewal. There are efforts underway to preserve and potentially even restore the site to its original form. Elsewhere in the world, replicas such as Newhenge have sprung up.
   We can divide the development of Stonehenge into several phases covering a span from around 3100-3000 BCE and ending around 1100 BCE. An embankment and ditch enclose the first structure identified by the Aubrey Holes. There was probably a ceremonial gateway on roughly the present alignment. There may have been a circular building in the centre, but no conclusive evidence for this survives. The site was in use for about 500 years before being abandoned. The second development phase occurred around 2100 BCE when Stonehenge was radically rebuilt. Bluestones from the Preseli mountains 240 miles away in southwest Wales were set up at the centre, forming an incomplete double circle. The entrance was widened and a pair of Heel Stones erected. The nearer part of the Avenue was built, aligned with the midsummer sunrise. The bluestones weigh up to 4 tons each and about 80 stones in all were used. One of the present theories speculates that the stones were dragged by roller and sledge from the inland mountains to the headwaters of Milford Haven. From there they were sailed along the south coast of Wales, then up the Rivers Avon and Frome to a point near present day Frome in Somerset. From this point, the stones were probably hauled overland to a place near Warminster in Wiltshire, approximately 6 miles from the site; next, floated down the River Wylye to Salisbury, then up the Salisbury Avon to West Amesbury, leaving only a short 2 mile drag from West Amesbury to the final site.
   The third phase of Stonehenge about 2000 BCE saw the arrival of the sarsen stones, which were arranged in an outer circle with a continuous run of lintels. Inside the circle five trilithons were placed in a horseshoe arrangement, whose remains we can still see today. The axis of the monument pointed to the midsummer sunrise and was marked externally by a single Heel Stone inside a smaller circular ditch. The giant sarsen stones which form the final phase outer circle each weigh as much as 50 tons each. To transport them from the Marlborough Downs, roughly 20 miles to the north, was a problem of even greater magnitude than that of moving the bluestones. Most of the way, the going is relatively easy; but modern studies estimate that at least 600 men would have been needed just to get each stone past the steep Redhorn Hill. Once on site, a sarsen stone was prepared to accommodate stone lintels along its top surface. Each was dragged until the end was over the prepared spot. Great levers were inserted under the stone and it was raised until gravity made it slide into the hole. Rope and pulley assemblies were attached to the top and teams of men pulled from the other side to raise it into the full upright position where it was secured by filling the hole at its base with small, round packing stones. The lintels were lowered into place with tackle and blockwork or dragged up temporary earthen ramparts and secured vertically by mortice and tenon joints and horizontally by tongue and groove joints.
   The next stage involved the selection of about twenty bluestones, which were shaped and erected in an oval setting inside the sarsen horseshoe. At least two miniature copies in bluestone were made of the great sarsen trilithons. Their components still survive. Sometime later, around 1550 BCE, two rings of holes were dug to form once again a double circle of bluestones but the project was abandoned. The final stage of Stonehenge took place soon after 1550 BCE when the bluestones were rearranged in the horseshoe and circle that we see the remains of today. About 60 bluestones were used, but very few survive. The largest bluestone, the Altar Stone probably stood as a tall pillar on the axial line of the monument.
   In Geoffrey of Monmouth's Historia, Aurelius Ambrosius sends his brother Uther to bring the Giant's Dance from Mount Killaraus in Ireland at the suggestion of Merlin to be used as a memorial for the dead slain in the Night of the Long Knives. It is possible that this account contains some trace of an oral tradition that it was transported over water from a great distance as discussed above. The association with Merlin erecting the henge suggests such a tradition as the island is sometimes known as Myrddin's Enclosure.
   It is recognized today that Stonehenge was built as a solar - lunar calendar. The Roman historian Diodorus Siculus wrote that the Sun God visited the circle once every 19 years. The movement of the nodes of the moon is in a gradual circling of the solar ecliptic in contrary direction to the planets (the lunar node is actually the point where the path of the moon crosses the path of the sun, the ecliptic). This 'cycle' is eighteen years and seven months. In three of these nodal periods, 56 years, the moon completes a circuit of eclipses and then begins the same sequence again. The arrangement of uprights at Stonehenge is designed to mark this periodicity of 18 years and seven months, which Diodorus Siculus rounded to 19 years. In his Stonehenge Decoded, Gerald S. Hawkins claimed that ten of the alignments of the circle point to significant positions of the sun, within an accuracy of under one degree, while a different set of fourteen alignments point to extreme positions of the moon. From his observations, he surmised that when the winter moon rises over the horizon above the Heel Stone, then an eclipse of sun or moon will follow. The eclipse of sun and moon is one of the obvious pointers to the 19 year cycle of Diodorus Siculus. Hawkins' conclusions have been subjected to heavy criticism, yet there is little doubt that Stonehenge was built as a ritual centre, marking out significant solar-lunar positions, the most important is the 19 year cycle.
   It has been proposed by Sir Norman Lockyer and also by Cotsworth that a fallen stone, now called the Slaughter Stone, formerly stood erect in line with the vertical Friar's Heel stone, to align the amplitude of the Summer Solstice. Lockyer claimed that not only did the sun rise on June 21st, at one end of the axis or line which divides the circle of Stonehenge, but that it also appeared to set at the other end of this same axis at the time of the shortest day (21 December); for through the resultant aperture formed by the Slaughter and Friar's Heel, the sun could be seen to set on 21 December.
   Stonehenge is still an awe-inspiring sight and no traveler to Britain should miss the opportunity to see it.