Stonehenge is a group of stones standing on the Salisbury Plain. ‘Henge’... simply means hang! The word 'hanger' is still used for a large building with no internal supports. The roof, supported by the Sarsen Circle of stones, is pre-eminent among megalithic monuments in the British Isles. This great prehistoric structure is enclosed by a circular trench. The outermost ring is a circle of sandstones about 13.5 ft high connected by lintels; the second group is a circle of bluestone menhirs; the third is horseshoe shaped; and the innermost grouping is an ovoid circle including the 'Altar' Stone. Stonehenge was build around 3500 BC by semi-nomadic peoples who populated the Salisbury Plain. The first stone to be placed was the Heel Stone. 200 years later 80 blocks of Bluestone were brought from a quarry almost 200 miles away. These blocks were likely transported by rafts along the Welsh coast and up local rivers, and finally dragged overland to the site. At some point earlier construction was dismantled and work began on the final phase of the site. The Bluestones were moved within the circle and the gigantic Sarsen stones that give Stonehenge its distinctive look were installed. Some of these massive stones weigh as much as 26 tons! The circle is aligned with the midsummer sunrise, the midwinter sunset, and the most southerly rising and northerly setting of the moon. For more info visit the Stonehenge English Heritage site.