The lead and silver mines at Charterhouse, were first operated on a large scale by the Romans, from at least AD 49. At first the lead/silver industries were tightly controlled by the Roman military, but within a short time the extraction of these metals was contracted out to civilian companies, probably because the silver content of the local ore was not particularly high. There was also some kind of 'fortlet' here in the 1st century, and an amphitheatre. The Roman landscape has been designated as a Scheduled Ancient Monument.