A team of geologists from Britain have pinpointed the exact quarry that Stonehenge’s innermost circle of rocks came from. It’s the first time that a precise source has been found for any of the stones at the prehistoric monument. Robert Ixer of the University of Leicester and Richard Bevins of the National Museum of Wales painstakingly identified samples from various rock outcrops in Pembrokeshire, Wales.
For nine months the pair used petrography — the study of mineral content and textural relationships within rocks — to find the origins of Stonehenge’s rhyolite debitage stones. These spotted dolerites or bluestones form the inner circle and inner horseshoe of the site. They found the culprit on a 65-metre-long outcropping called Craig Rhos-y-Felin, near Pont Saeson in north Pembrokeshire. It lies approximately 160 miles from the Stonehenge site.
Having said all that, how the F*** did these people get these rocks from point A to point B over 5,000 years ago using a method that we haven't been able to definitively figure out 5,000 years later.
Source -> http://www.wired.com/wiredscience/2011/12/stone-henge-rocks-origins/
Earlier Stonehenge link -> http://www.dannyfinnegan.com/2011/11/newly-discovered-pits-add-mystery-to.html