Its high granite walls dominate this area of the moor. Constructed originally between 1806 and 1809 by local labour, to hold prisoners of the Napoleonic Wars, it was also used to hold American prisoners from the War of 1812.
On April 6, 1815, although the wars had ended with the Treaty of Ghent in December of the previous year, many American prisoners of war still remained. Seventy were unfortunate enough to be massacred in the prison at the behest of the allegedly drunken British officer in charge, who thought they were attempting to escape.
Dartmoor was reopened in 1851 as a civilian prison, and has contained some of Britain's most serious offenders ever since. It has a (misplaced) reputation for being escape-proof.