El Peine del Viento when the swell is up

At the far western end of the bay, past Ondarreta beach and under Monte Igueldo, Eduardo Chillida's three steel forms are anchored straight into the rock. The pink granite terrace they sit on is Luis Peña Ganchegui's work and it is part of the sculpture: holes in the paving connect to the sea below, and when the swell comes in the water forces air and spray up through them.

It is the most photogenic corner of San Sebastián, and it changes completely with the sea. On a calm day it is a clean graphic set — rust, granite, blue water, the horizon line. When the Atlantic is working, the same spot becomes drama: spray to head height, wet stone reflecting the sky, and the possibility of one frame you cannot plan.

The terrace faces west, so the sun sets straight in front of you — the sculptures go to silhouette against the water and the whole thing rims with orange. That is also the busiest hour; the alternative is early morning, when the light comes over your shoulder from the town and nobody is there.

Check the tide table and the swell forecast before you go: at high tide with a big swell the terrace is genuinely dangerous and it is sometimes closed off. Wave photography here has cost people their footing. Keep well back from the edge, expect salt on the front element, and bring a cloth. It is a twenty-five minute walk along the beach from the centre, or a short bus ride.