Little beach undersells it — Prainha is really a chain of little beaches: a run of pocket coves strung between Alvor and Três Irmãos under some of the most sculpted red-gold rock on the Portimão coast. Stacks stand in the shallows, and at low tide the coves connect through carved tunnels and archways, so the beach you’re on keeps becoming the next one. It sits below a clifftop resort, with stairways bringing you down through the pines.
The rock is the subject here. This is the compressed, ornamental version of the Algarve’s limestone coast — arches, windows and wave-cut passages at wading distance rather than boat distance — with clear, usually calm water at their feet.
When to go: low tide is non-negotiable if you want the tunnels open and the coves linked, so check the tables before you go. Golden hour turns the already-red rock feverish, and mornings get you the carved passages before the towels arrive. High tide shrinks the coves to slivers and closes the connections.
Who it’s for: photographers who want Ponta da Piedade’s geology at towel height; snorkellers working the rock margins; families based around Alvor — with the caveat that stairs and tide-cut coves need watching with small kids.