A winding stone bridge links the mainland to this rocky islet, followed by 240 steps up to the small hermitage of San Juan de Gaztelugatxe. The chapel dates back to the 10th century, although it has been rebuilt multiple times following fires and pirate attacks. Even if the chapel is closed (which it often is), the climb is worth it for the stunning sea views, the cliffs carved into arches, and the remote, windswept feeling at the top - Game of Thrones fans will recognise the setting as Dragonstone. It’s about a 45-minute drive from Bilbao. You can also take a bus to Bermeo, a fishing town nearby, and continue by taxi or local bus. The trail is steep and uneven, so good shoes help.

This museum traces Basque history from the Paleolithic to today, covering culture, language, and daily life. Most signage is in Basque and Spanish, but English leaflets are available for the main exhibits.

Built from the late 14th to the 15th centuries, the Santiago Cathedral is the city’s oldest major church, dedicated to Saint James (Santiago), Bilbao's patron saint. The building features a mix of different styles: its core is Gothic (nave, vault, cloister), a grand Renaissance portico was added in the 1500s, while much of the façade and tower with spire were rebuilt in a neo-Gothic style in the late 1800s by Severino de Achúcarro. Inside, you’ll see three naves, several side chapels, the Gothic cloister accessible via the Door of the Angel ('Puerta del Ángel'), and beyond the main altar, there’s an ambulatory with chapels. Floods in 1983 caused damage, but the cathedral was restored and reopened around 2000.