The most bizarre experience of a July visit to Orkney and Shetland took place on Unst, on the road that leads towards Hermaness and Muckle Flugga, the northernmost point of the British Isles. It manifested itself as a two-seater cane sofa with cushions and a cotton throw; beside it, a cane table with two mugs, a television set and a small food cabinet labelled 'Hot Snacks', its contents somewhat ill-defined. There was also a smaller table on which stood a potted plant, an empty whisky or sherry bottle and a box of tissues. On the wall, a clock with an octagonal wooden case: round three sides of the room, at the top of the wall, a lace hanging which figured repeated pairs of geese. Only it wasn't a room but a bus shelter with a bare concrete floor. Who? Why? The furnished shelter was oddly reminiscent of the displays to be found in Shetland at the Lerwick museum, or on Orkney at the Visitors' Centre at Maeshowe, of a typical islander's living room of times past. But here no explanation was on hand for what was effectively an instance of public art: no personal belongings, no poster, no collecting-box or (sign of the times) evidence of sponsorship. No one. The peaty moorland stretching away. A small loch glimmering in the background.

The incongruity of this tableau was heightened by the context of a spare landscape in which any object stood out naturally, without such extravagance: the shelter ...