Carew Tidal Mill

Standing beside the creek at Carew, this restored 11th-century tidal mill is one of the best-preserved examples in Wales. The massive stone structure harnesses the twice-daily tides to power its grinding wheels - a proper feat of medieval engineering that still works today. When the tide comes in, water fills the mill pond. As it recedes, the rush of water turns the wheel and millstones grind into action.

History buffs will love the guided tours that explain how monks first built this mill nearly a thousand years ago. The machinery is fascinating to watch in operation, though you'll need to time your visit with the tides to see it working. Children enjoy the hands-on exhibits about flour production, but it's not huge so an hour covers it well.

Coupled with Carew Castle just across the causeway, it makes for a cracking half-day out from Tenby. The setting beside the tidal creek is lovely for a picnic, and you can walk the short circular path around the millpond. Those staying at nearby holiday parks like Cross Park Holiday Village or Masterland Farm will find it an easy drive - though parking can get tight in summer. Free admission makes it well worth the detour, especially if you're already exploring this corner of Pembrokeshire.