One of the most remarkable prehistoric sites in England, Grime's Graves is a Neolithic flint mining complex covering around 90 acres of the Breckland forest. From the surface it looks like a lunar landscape — hundreds of shallow craters in the earth, each one the collapsed mouth of a mine shaft sunk four thousand years ago. English Heritage manages the site, and visitors can descend a ladder into one of the excavated shafts to see the antler picks left behind by the miners and the galleries they carved into the chalk.
The flint extracted here was used to make tools and weapons across much of Britain. The name has nothing to do with graves — in Old English, "grim" was a byword for the god Woden, and the unusual landscape was assumed by later settlers to be the work of something supernatural.
The site is eight kilometres northwest of Thetford along the B1107. Opening times vary seasonally; check English Heritage's website before visiting.