09:00 — La Concha at its calmest
Walk the full curve of La Concha promenade beneath the white Belle Époque railings, with Santa Clara island floating in the middle of the bay. This is one of Europe's most beautiful urban beaches, and early morning — swimmers, dog walkers, low light — is its best hour.
11:00 — Peine del Viento and Monte Igueldo
At the bay's western tip, Eduardo Chillida's Peine del Viento (Comb of the Wind) sculptures grip the rocks as waves blast through blowholes at your feet. Ride the century-old wooden funicular up Monte Igueldo for the definitive postcard view over the whole shell of the bay.
13:30 — First pintxo crawl
Head into the Parte Vieja. The rules: one or two pintxos and one drink per bar, then move. Classics to hunt down include the gilda skewer, seared foie, spider-crab tartlets and anything the chalkboard calls 'de la plancha'. Plaza de la Constitución, the old bullring square with its numbered balconies, makes a natural base camp.
17:00 — San Telmo and the old town
The San Telmo Museum, set in a 16th-century convent at the foot of Monte Urgull, tells the Basque story properly. Browse the old town's streets afterward — txapela beret shops, pastry windows, the arcades around the Bretxa market.
20:30 — The serious dinner
Either book ahead for one of the celebrated tasting-menu houses that made this region a pilgrimage — Arzak and Akelarre in the city, Mugaritz just outside — or simply keep grazing: a second pintxo route through Calle 31 de Agosto is a Michelin experience paid in small change.