A rewarding loop from Bilbao combining the historically significant town of Gernika (Peace Museum, sacred oak tree), the Urdaibai Biosphere Reserve (wetlands, birdwatching), the dramatic San Juan de Gaztelugatxe islet, and the charming surf village of Mundaka.
The loop from Bilbao through Gernika, the Urdaibai Biosphere Reserve, and the Atlantic coast combines historical significance, outstanding natural scenery, and some of the most dramatic coastal landscapes in northern Spain — all within 45 kilometres of the city.
Gernika (Guernica in Spanish) sits 33 kilometres northeast of Bilbao and is accessible by EuskoTren from Bilbao Atxuri station in approximately 45 minutes, a scenic ride through Basque farmland. The town was devastated by Axis bombing on 26 April 1937, an event that inspired Pablo Picasso's painting of the same name. The Gernika Peace Museum (Museo de la Paz, Foru Plaza 1) tells this history with considerable restraint, requiring around 90 minutes to visit properly. Admission costs €5. The sacred oak tree (Gernikako Arbola) and the Casa de Juntas — the historic assembly hall of the Basque parliament — are a short walk from the museum and free to visit.
The Urdaibai estuary spreads south and east of Gernika, a UNESCO Biosphere Reserve covering 22,000 hectares of wetlands, dunes, oak forests, and tidal flats. The reserve is among the most important bird-migration stopover points on the Atlantic flyway. The Urdaibai Bird Centre near Gautegiz Arteaga offers guided birdwatching programmes and an estuary viewing platform.
San Juan de Gaztelugatxe is a rocky islet 20 kilometres west of Gernika, connected to the mainland by a dramatic stone causeway with 241 steps leading to a 10th-century hermitage at the summit. Timed entry permits are now required and must be pre-booked through the Basque Government tourism portal (free). The climb takes about 15 minutes each way and involves uneven stone steps. The site featured as a filming location for Game of Thrones.
Mundaka, a small surf village at the mouth of the Urdaibai estuary, is famous for producing one of Europe's finest left-hand barrel waves. The harbourside square and seafood restaurants overlooking the estuary make it the natural lunch stop for the itinerary.
Highlights
- Gernika Peace Museum
- San Juan de Gaztelugatxe
- Mundaka surf village
- Urdaibai estuary and wetlands
- Playa de Laga wild beach
Tips for visiting
- Pre-book timed entry to San Juan de Gaztelugatxe via the Basque Government tourism portal — walk-in access is restricted from April to October.
- EuskoTren from Bilbao Atxuri station reaches Gernika in 45 minutes; a hire car is needed to continue to Gaztelugatxe and Mundaka efficiently.
- The Gernika Peace Museum is closed on Mondays; plan the itinerary to arrive on another day.
- Visit Gaztelugatxe before 10:00 or after 17:00 to avoid peak-hour crowds on the narrow causeway steps.
- Mundaka's harbourside restaurants serve excellent grilled fish — lunch at the port makes a natural anchor for the afternoon.
When to visit
Spring (April–June) and early autumn (September–October) are optimal for combining coastal scenery, birdwatching, and comfortable walking. Gaztelugatxe is heavily crowded in July and August; weekday visits in the shoulder season are significantly quieter.
Frequently asked questions
Is a car necessary for this day trip from Bilbao?
EuskoTren reaches Gernika without a car. For San Juan de Gaztelugatxe and Mundaka, a hire car is strongly recommended as bus connections between these coastal sites are infrequent; organised tours from Bilbao cover the full loop.
Does San Juan de Gaztelugatxe require pre-booking?
Yes. From April to October, timed entry permits are required and should be booked through the Basque Government's tourism website. Entry is free but the reservation is mandatory and spaces are limited.
What is the Gernika Peace Museum about?
The museum documents the Nazi and Fascist bombing of Gernika on 26 April 1937 and its legacy as a symbol of peace. It provides historical context for Picasso's painting and covers the broader history of the Basque Country during the Spanish Civil War.
How long does the climb to the Gaztelugatxe hermitage take?
The descent from the car park and ascent to the hermitage involves 241 steps and takes approximately 15–20 minutes each way. The steps are uneven stone and require reasonable mobility; the view from the top across the Atlantic is exceptional.
What is the Urdaibai Biosphere Reserve?
Urdaibai is a UNESCO Biosphere Reserve covering 22,000 hectares of wetlands, estuary, oak woodland, and coastline east of Gernika. It is one of the most important bird-migration stopover points in the Bay of Biscay and home to otters, marsh harriers, and wintering waterfowl.