Dunans Castle

A crumbling fortress on the shores of Loch Fyne, Dunans Castle sits about three miles south of Cairndow - accessible by a decent walk through woodland or a bumpy track if you're keen on a drive. What you'll find is a 13th-century ruin that's properly atmospheric, with enough walls still standing to give you a genuine sense of medieval life on this remote stretch of Argyll coast. The views across the loch are worth the trek alone.

It's a place for history types and walkers rather than casual tourists. Kids will manage the walk fine, though there's not much to do once you're there beyond poking around the stonework and taking photos. Allow an hour, maybe ninety minutes if you're the type to sit and soak it in. Access is free and unrestricted, though there's no facilities or visitor infrastructure to speak of - bring a map and decent shoes.

If you're staying at one of the caravan parks in the area - Strathlachlan or Glendaruel are closest - Dunans makes a decent half-day excursion to break up a park holiday. Cairndow itself is small and quiet, so this feels less like a tourist tick-box and more like stumbling onto actual local history. The castle grounds are wild and overgrown, which is part of the appeal. Not Instagram-friendly, which is precisely why it's worth visiting.