Considerable group effort was needed to raise these first 'buildings' - many stones weigh several tons or more, sometimes moved many miles. They were built at the time of the first great social transition - when Man ceased being a hunter-gatherer like other animals, and began to farm. This social innovation was to last the people of Britain until the Industrial Revolution, thousands of years later.

With social organisation, and settling down in one place, the people could organise the effort of many individuals in the construction of these monuments, which probably had some ceremonial and ritual purpose too. From 4000 BC through the intervening years almost until the birth of Christ Neolithic people constructed more than a thousand stone circles and rows in the British Isles.

Yet megalithic construction was not confined to this region - the legendary stone rows at Carnac, Brittany in France are peerless, and mainland Europe has many sites. Britain and Ireland, however, have an abundance of megalithic sites to see and marvel at. The best known British site is, of course, Stonehenge, auctioned in September 1915 for the princely sum of £6600, but since passed into the care of English Heritage. Together with the massive stone temple of Avebury, these two Wiltshire sites are the biggest of the British Isles. together with the large site at Callanish on the Isle of Lewis in the Outer Hebrides.