One of Edinburgh’s many atmospheric old cemeteries, Old Calton is dominated by the tall black obelisk of the Political Martyrs’ Monument, which commemorates those who suffered in the fight for electoral reform in the 1790s. In the southern corner is the massive cylindrical grey stone tomb of David Hume (1711–76), Scotland’s most famous philosopher.

Hume was a noted atheist, prompting rumours that he had made a Faustian pact with the devil; after his death his friends held a vigil at the tomb for eight nights, burning candles and firing pistols into the darkness lest evil spirits should come to bear away his soul.