There is a Sonehenge 3D replica in Wahington (state) on the north shore of the mighty Columbia River. I don't recall the town or county. East of Portland. It is a scale model built outa concrete by some rich guy to honor the dead soldiers in WW One from Washington. Really cool! You can walk around in it for free and thus get an idea of the scale and some magnitude. Past just getting there, the original on the Salisbury Plain is not always accesible I hear and is in quite a state of decay. For those of you all in the USA, the one in Wash. is a reasonable alternative. Read the novel SARUM by Edward Rutherford. There is a lengthy section about the building of Stonehenge from a young mason's POV.