The last type of Megalithic structure was the Cromlech., these are found only in the
British isles and they were the
setting for religious rites. (note ritual areas as the scene of artistic
endeavors like in Lascaux). It is generally respected that the huge
effort to create these was the sort of effort that is generally only
compelled by religious faith (something we will often see throughout
history)
The last and most famous cromlech is called Stonehenge, in Southern
England. Stonehenge can be considered to be a work in progress for
thousands of years.
3500 - 2900 BCE a nearly continuous circle (henge) was dug into the
chalk ground.
3300 - 2140 BCE a silted ditch was added
2580 - 1890 BCE An avenue to the Avon river was created
2850 - 2200 BCE The sandstone (sarsen) circle of Trilithons was
erected. "Trilithons are post and lintel formations of stone.
2480 - 1940 BCE A bluestone circle and horseshoe of stones was built
within the ring of Trilithons.
2030 - 1520 BCE Rings of outer stones were added and a center altar
stone
Stonehenge was originally aligned so that it’s heel stone (which
was there since the beginning, would align with the major and minor
northern moonrises. However at some later point the heelstone was moved
so that it matched the rise of the sun during the summer solstice.