Glenacardoch, dun site

The ruins of this Iron Age dun sit on a hillside above Tarbert, commanding views across the water to Kintyre. It's not much to look at from a distance - just stone foundations and scattered rubble - but walk up and you realise you're standing inside a proper fortress, with walls that once stood much higher. The circular layout is still obvious, and on a clear day the defensive position makes total sense.

This is one for archaeology enthusiasts or anyone interested in how Scotland's ancient peoples actually lived and fought. Casual tourists will spend twenty minutes here, tops, then wonder why they bothered with the climb. But if you're into Iron Age history, it's worth the detour from Tarbert. The walk up takes ten minutes from the road - manageable but a bit boggy depending on recent rain. There's no visitor centre, no signs, no facilities whatsoever, so come prepared.

It fits nicely into a wider exploration of Argyll's archaeological sites if you're basing yourself at one of the local holiday parks. Killegruer and Muasdale are both close by, making this a sensible half-hour stop between other attractions. Go mid-morning when the light's best for photography and the midges are less vicious. Free to visit, obviously - there's nobody to charge you anyway.