With the Pentland Hills climbing to the west, the Moorfoot Hills to the south, and Edinburgh right on its doorstep, Midlothian is high up on the agenda for many visitors to Scotland. South of Edinburgh’s city bypass lies a swathe of former coal-mining country. The pits were closed in the 1980s, and former mining communities like Dalkeith, Newtongrange, Bonnyrigg and Gorebridge have become dormitory suburbs of the city. Gorebridge is a rather sleepy suburb these days. In the 19th century it produced gunpowder for Wellington’s armies and Nelson’s warships, and its peace was occasionally shattered by accidental explosions. You can see the scanty remains of the gunpowder mills nearby, but Gorebridge’s real attraction is a grand Georgian mansion built for a dynasty of Scottish magnates: Arniston House.