Grimes Graves, Norfolk, England. Another historic site I used to manage.

Grime’s Graves is the only Neolithic flint mine open to visitors in Britain. This grassy lunar landscape of 400 pits was first named Grim’s Graves by the Anglo-Saxons. It was not until one of them was excavated in 1870 that they were identified as flint mines dug over 5,000 years ago.

Set amid the distinctive Breckland heath landscape, which is also a Site of Special Scientific Interest and a habitat for rare plants and fauna.

The site is open to the public and managed by English Heritage

Visitors can descend 9m (30ft) by ladder into an excavated shaft to see the jet-black flint that the neolithic people excavated extensively – the first industrial revolution in England.