Charco de la Laja

Waves break on the outer rocks metres from the water you swim in. Charco de la Laja is a basin of dark volcanic rock carved by the sea itself, and at high tide the Atlantic spills over the rim and refills it.

On a calm day you float in clear salt water with the swell booming behind the rocks. On a rough one the whole pool turns to white water and noise. Then the visit becomes a matter of standing on the steps and watching the ocean do what made the pool in the first place.

There is nothing built around it. Bare rock, a few flat places to spread a towel, the sea and the cliffs of the north coast.

• A green, yellow or red signal gives the day's sea conditions. Swim only on green.
• Read the warning signs along the road before you go down.
• About 40 steps lead from the road to the pool, and there is no wheelchair access.
• No toilets or showers at the pool; the nearest toilets are about 680 m away. No drinking water nearby, so bring your own.
• Space for a towel on the rocks is limited, and the bare rock has no shade.

The pool lies at the end of a road on the coast of San Juan de la Rambla. Seven to ten parking spaces sit at the end of the road beside the entrance, with more along the main road. Two further car parks, one on a dirt surface, are about 275 m and 330 m away in a straight line.

By bus, the stops Los Palomos and La Marina are about 300 m and 340 m away.

From the road, a flight of about 40 steps drops to the pool. The warning signs stand along the road on the way in: read them before you start down.

Best: a day of calm sea with the green signal showing.

Avoid: days of heavy swell and a red signal.

When big waves reach the pool they set up currents strong enough to pull a swimmer out to sea, and on those days the place is for watching only. This coast faces the open Atlantic and takes its heaviest swell in winter; at midday in summer the bare rock gives no shade.