The earliest known developments at
Stonehenge itself were the construction of a
circular earthen ditch and bank in the Middle
Neolithic period, close to 2950 BC. It had an
entrance to the northeast and another to
the south. An inner ring of 56 pits, known
as the Aubrey Holes, were probably dug at
around the same time. Archaeologists still
debate whether any or all of these pits held
permanent timber posts from the outset.