Walk on the dry sand at Porth Oer and it squeaks underfoot — the grains are shaped so they whistle as they move, which gives the cove its English name, Whistling Sands. It’s a sheltered National Trust beach near Aberdaron on the tip of the Llŷn, with a seasonal café above. A steep path leads down; there’s a car park at the top.

© Eirian Evans / Geograph · CC BY-SA 2.0