San Sebastián is a small city — the Parte Vieja, La Concha beach, and the main commercial streets are all within easy walking distance of each other. For most visitors, the city is almost entirely walkable. The Zurriola beach and Gros neighbourhood across the river are a fifteen-minute walk from the old town.
For Monte Igueldo, the funicular is the most enjoyable way up (departures every fifteen minutes in season). The city bus network (Dbus) covers the wider urban area. Taxis are reasonably priced. Bikes can be rented from several shops near the waterfront; the city has a decent cycle lane network along the waterfront and into the newer neighbourhoods.
The coastal Euskotren narrow-gauge railway is useful for day trips to nearby towns like Zarautz, Getaria, and Zumaia along the coast, and to the French border at Hendaye.