Stonehenge:
* New geological research is currently being carried out to identify the sites of origin more accurately. How the stones were transported for over 250km (156 miles) to Stonehenge remains unknown, but it is probable that a combination of transport via water networks and hauling over land brought them to the site. The larger sarsen stones are a type of sandstone, a stone found scattered across southern England. Most archaeologists believe that these stones were brought from the Marlborough Downs, where great quantities of sarsens still lie scattered in the landscape, although the exact location of their origin is unknown. * Existing evidence suggests that the 'bluestones' were the first stones to be erected at Stonehenge, in a double circle. From the stones that remain on site today, it can be seen that some were shaped to enable them to fit together with others. This suggests that either in this first arrangement or perhaps at another site altogether, these bluestones formed a lintelled arrangement. * The stones were erected in two arrangements – an inner horseshoe of five trilithons (two vertical stones capped by a third horizontal lintel) and an outer circle of 30 uprights with continuous lintels. * The stones weigh on average 25 tonnes and were transported to the site, dressed, erected and secured together with sophisticated joints – a remarkable achievement. The sarsen stones were worked using hammer-stones and mauls. * At the same time or earlier, the unshaped stones close to the entrance were raised, along with the four Station Stones on the periphery of the monument. These stones may relate to the setting out of the monument, or to solstitial and lunar alignments. * Near the centre of Stonehenge was the Altar Stone, now fallen, which may have stood upright. Once the stone settings were erect, the Avenue was built to connect Stonehenge with the River