I was able to attend both Equinoxes, and both Solstices at Stonehenge in 2006. Meeting many interesting people, who celebrate there for various reasons. This includes Druids and Pagans. Stonehenbe clearly demostrates, by alignments to ALL the maxima and minima positons of the Sun and Moon at the Solstices and Equinox, full understanding of spherical geometry, and the movement of the Earth orbit, and the Moons orbit of Earth. The most likely explanation of this knowledge, and construction over 2000 years, is the Anunnaki. The ancient Gods, visitors from another planet, who developed early man, civilisation, 360 degrees, constelation names and the Zodiac.
Try a search on Google for Anunnaki
The original creation story is called the Enuma Elish.
It is also possible that the Beaker people, associated with Stonehenge 3 circa 1500BC were refugees from a Nuclear War, which destroyed Sodom and Gomorah. After which people fled from a radioactive cloud poluting the Sumerarian Civilisation, in Mesopotamia, Iraq.