Carsluith Castle

The ruins of a 15th-century tower house stand alone in farmland south of Castle Douglas, commanding views across the Solway Firth towards England. What you get here is honest - a roofless stone shell, four storeys high, with enough remaining detail to read its history but not much to delay you long. The castle was built by the McCullochs and held its own against various raids and sieges before falling into disrepair. Inside, a spiral staircase climbs through darkness, and you can make out fireplaces and window seats along the walls. It's free to visit and there's no gate or fence, so you come and go as you please.

This suits history-minded walkers more than families with small children. You'll need decent boots - the approach crosses rough ground - and the interior isn't safe for young kids scrambling about. Give it 30 to 45 minutes, maybe longer if you're photographing the stonework or taking time with the views. Go in dry weather; the spiral stairs are slippery when wet.

As part of a Dumfries & Galloway park holiday, it works well. Auchenlarie Holiday Park and Drumroamin Farm are both within three miles, so you can fit it into a morning before heading elsewhere. The castle feels like a proper off-the-beaten-track detour rather than a scheduled attraction - which is exactly why it's worth the short drive from Castle Douglas.