Windmill Quarry

The water at Windmill Quarry is an almost unsettling shade of turquoise - the kind of blue you'd expect to find in the Mediterranean, not inland Argyll. It's a former quarry that's flooded over, creating a proper swimming spot just a couple of miles from Oban, and on a decent day it's genuinely striking.

You can swim here, which is the main draw. The water's cold - Scottish cold - so a wetsuit isn't just sensible, it's essential unless you fancy a quick gasp-and-out approach. There's a kind of Wild Atlantic energy to it, even if you're not actually on the coast. The quarry walls rise up around you, giving it an almost amphitheatre-like feel, which means the light changes dramatically depending on what time you visit.

It works best for open water swimmers and anyone keen on a genuine adventure rather than a manicured lido experience. Families with younger kids might find it a touch too raw - there's no shallow end, no lifeguards, no cafe. But teenagers who like a bit of edge to their holiday will rate it.

If you're basing yourself at Argyll Kayaker Cove or Sunnybrae Holiday Park nearby, it's worth factoring in as a morning or late afternoon activity rather than a full day thing. Allow an hour or so, longer if you're actually getting in the water. Check conditions first - after heavy rain it can look less inviting, and wind can make it properly choppy. Summer months are your best bet, though even then bring a towel and a warm layer.