So....maybe this was a bit more than simply a religious/ceremonial site...?
The Discovery Of 15 New Monuments Has ‘Transformed’ The Mystery Of Stonehendge
....Researchers used a noninvasive technique of ground-penetrating radar and 3D laser scanning to make detailed maps of the subsurface without having to dig holes. The survey, called the Stonehenge Hidden Landscape Project, said researchers found 15 new monuments near Stonehenge, a 4,000-year-old ring of standing stones located in Wiltshire, England. Scientists discovered several man-made features, including henges, pits, ditches and barrows -- mounds of earth and stone used to mark a grave or graves -- according to Smithsonian Magazine.
“This is among the most important landscapes, and probably the most studied landscape, in the world,” Vince Gaffney, a professor at the U.K.'s University of Birmingham and lead researcher of a recently completed four-year survey of Stonehenge, told Smithsonian Magazine. “The area has been absolutely transformed by this survey. (It) won’t be the same again.”
The research team also found gaps in the nearly two-mile-long Stonehenge cursus, a name given to large, parallel, Neolithic ditches found all over the U.K. that archaeologists consider some of Britain’s oldest prehistoric monumental structures. The purpose of cursuses has long been debated, but scientists have suggested that they served as processional routes. Cursuses often follow astronomical alignments, as is the case with the Stonehenge cursus, which traces the sunrise on the Spring and Fall equinoxes.
The 15 hidden monuments near Stonehenge suggest the site wasn't an isolated place visited only on special occasions, as science has previously proposed, but was once bustling with all kinds of activity. “The perceived wisdom was driven by the monuments we knew about,” Gaffney told Smithsonian. “We’ve put in the data between the monuments.”
Read more: http://www.ibtimes.com/mystery-stonehenge-discovery-15-new-monuments-has-transformed-famous-landmark-1671076#ixzz3BdzySXNA
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The part that stood out was their technique for finding these new monuments: ground-penetrating radar. The "3D laser scanning" is likely just LiDAR which is something being used extensively now in normal land surveying. It's the radar tech that's most important.
I remember an early Space Shuttle mission where they had a radar imaging device on board. I had to look it up again, but it's called the Shuttle Imaging Radar-B (SIR-B.)
I can remember being extremely excited by the results NASA released, such as how it showed ancient riverbeds under the Sahara, and in recent years showing the location of possible pyramids and other ruins in the Amazonian rain forests. I long for the day when we fund scientific endeavors like that and let us all see the images (as in, don't let the DoD squirrel away any of it.) The things still out there on our ancient planet we could find...
Thanks for sharing! 
http://www.jpl.nasa.gov/news/news.php?feature=422
