HERMIT'S CASTLE ( www.undiscoveredscotland.co.uk )

The remarkable Hermit's Castle, on the shore at Achmelvich near Lochinver in Sutherland.

This concrete folly was built in 1950 and, so the story goes, used for just one weekend before being abandoned.

Hermit's Castle can be described in many ways. It's been called Europe's smallest castle: though, despite the name, calling it a "castle" is stretching a point a little. A possibly more accurate description is that it is a remarkable concrete folly built in a Brutalist style that blends in a very surprising way into its rocky shoreside setting. What adds to its attraction is the slight air of mystery that surrounds it. The bare facts behind its presence in this location are fairly clear (though not universally agreed upon), but the important question about why it came to be built here seems to have gone unanswered.