Scottish Towns-Cities. (Dumfries.)

There are more than a few British towns that are best viewed in total darkness. Dumfries is one of them, but before its residents fill my pockets with red sandstone and hurl me into the river Nith, let me explain – by way of a trip to its famous camera obscura.

It’s lunchtime on a grey Wednesday in Dumfries, and I’m standing in the small, round, creaky-floored room at the top of a decommissioned windmill. It’s pitch black: I can see precisely nothing. Then the museum attendant (for the windmill is part of the Dumfries Museum) pulls a rope, an aperture opens above us, and Dumfries appears on the drum-like tabletop in the middle of the room.

There’s the red of the sandstone, the green of the grass, the silver of the cars that are snaking across the New Bridge. Birds swoop across the fulminating weir. It’s a projection (entering via a small shutter, light is reflected downwards by a mirror and, passing through a convex lens, casts an image on to the table), but the detail is exquisite and the movement of the people, water and birds has a fluidity that I’ve never seen on a television screen. “We try very hard not to look into people’s houses,” says the attendant hastily.

The camera obscura was built in 1836, a time when Scotland was rosy-cheeked with Enlightenment endeavour. It was funded by local astronomy enthusiasts, and is the oldest continuously operated one in Scotland. This makes it Dumfries’ second-biggest claim to fame – with a tip of the hat to its being named Scotland’s happiest town last October – the first being its association with Robert Burns.