Thornborough - 2000BC (or there abouts) an image showing the henges and their relationship with the post alignments and burial mounds.
More images here.
Thornborough is a triple-henge complex appearing to share the same astronomical alignment as the 3 main pyramids at Giza in Egypt. Does the Thornborough alignment mirror the Belt Stars of Orion?
More on this speculation here.
Air photo of the henges.
Maps & yet more text matterial here.