How Stonehenge was built:

Scientists have come up with a lot of theories on how Stonehenge was built. At first, it was thought that the Druids built Stonehenge. It's believed that the High Priests of the Celts constructed it for sacrificial ceremonies. Unfortunately, researchers have proven this theory linking Stonehenge's construction to the Druids impossible. With modern technology and tests, scientists have discovered that the builders completed Stonehenge around or over 1000 years before the Celts even inhabited the region. Druids would worship in marshes and forests, but it has been proven that Druids have used Stonehenge as a temple of worship and sacrifice, but it was not built by them.

Image from: http://www.laguz.net/phase3c.jpg

Another theory is that's going around is that three tribes built Stonehenge at three seperate times. This seems to be more of a logical theory. Around 3000 B.C., some of the first people to work on Stonehenge were the Neolithic agrarians. Scientists named them the Windmill Hill people after one of their works on Windmill Hill, which is quite close to Stonehenge's location. A little bit after the time of the Windmill Hill people, the Beaker People (a.k.a. Beaker Folk) came along. They were named the Beaker People (or Beaker Folk) because they bury Beakers with body of a dead person. Archaelogists believe that they were more warlike because they burried the dead with weapons also. The Beaker People were highly organized and industrious. They used sophisticated math concepts and managed their society by using a cheif system. Scientists believe they where sun worshippers who aligned Stonehenge with more exact certain important sun events such as mid summer and winter solstices. This is why Stonehenge was believed to have been built for astronomical reasons. The Wessex people were believed to come along around 1500 B.C. after the Beaker people. They were assumed to be the third tribe that help build/improve Stonehenge. They were by far one of the most advanced cultures in the Medditerrean at this time. They developed really quickly. They became well-organized traders that controlled all trade routes in most of Southern Britain. Scientists thought that they carved the carving of a Bronze Dagger found on one of the larger stones of Stonehenge. The Wessex culture was a very smart, wealthy, and well-organized culture. People feel as if their talents were required for the building of Stonehenge.
This theory was the best explained theory thus making people believe it more. This seemed more logical because otherwise the Druids would have probably finished Stonehenge in around 1200 A.D. because the stones are from other lands and their so heavy. If three different tribes built it, they would have enough slave workers to move the stones and when they died and lost a lot of men, they would just move on and leave Stonehenge the way it was/is.