A prehistoric chalk mound, part of the Avebury neolithic complex. Built around 4500 years ago, it’s one of the largest ancient man-made hills in the world. Nobody knows why it was built – it’s not a tomb, and probably wasn’t intended as a fortification.

Sadly, you can’t walk on the hill these days (it’s considered unstable, due to so many exploratory diggings by archaeologists and treasure hunters), but if you’re in Avebury, it’s worth taking a short trip outside the town to visit.