The sacred oak tree of Gernika, under which the lords of Castile traditionally swore to uphold Basque liberties, stands beside the Casa de Juntas assembly house where the Parliament of Bizkaia still meets. An essential pilgrimage site for understanding Basque political identity.
The Casa de Juntas and the Gernikako Arbola (Tree of Gernika) in Gernika-Lumo, Bizkaia, represent the most enduring symbol of Basque self-governance and the ancient tradition of Basque autonomy. For centuries, the oak tree at this site served as the sacred locus at which the Lords of Biscay, and later the kings of Castile following the union of the Crowns, swore to uphold the fueros — the ancient charters of laws and liberties that guaranteed the Basque people a degree of self-rule unique in Iberia. The ritual oath-taking under the oak dates to at least the 15th century and became the foundational act of legitimacy that any lord of Bizkaia had to perform. The current oak is a descendant sapling planted in 1986; its predecessor's centuries-old stump from the 18th century is preserved beneath a neoclassical domed pavilion — the Pavilion of the Old Tree, built in 1820 — in the same courtyard. The Casa de Juntas assembly building alongside it was constructed in 1826 in a neoclassical style and houses the oval parliamentary chamber of the Juntas Generales de Bizkaia, lined with portraits of historical lords and crowned by a magnificent stained-glass rotunda depicting the oak and the Basque coat of arms. The Parliament of Bizkaia still uses this chamber for ceremonial sessions. On 26 April 1937, during the Spanish Civil War, the German Luftwaffe's Condor Legion bombed Gernika in a deliberate strike against a civilian and culturally significant town, killing hundreds. The survival of the Casa de Juntas and the oak tree through that attack transformed the site into an even more potent symbol of Basque identity and resistance. Picasso's 1937 painting Guernica, displayed in Madrid's Reina Sofía museum, immortalised the bombing in world consciousness. Admission to the complex is free, and the site is among the most visited symbolic destinations in the Basque Country. Gernika-Lumo lies 35 kilometres east of Bilbao, easily reached by the Euskotren regional railway from Atxuri station, and the Casa de Juntas is typically combined with a visit to the Gernika Peace Museum on nearby Foru Plaza.
Why it matters
The Casa de Juntas and the Oak of Gernika have served since at least the 15th century as the constitutional symbol of Basque autonomy, where lords and kings swore to uphold Basque fueros (traditional laws); the survival of both through the 1937 Nazi aerial bombardment of the town made the site a worldwide emblem of Basque resistance and identity.
Highlights
- Gernikako Arbola — the living oak tree under which Basque fueros were sworn by lords and kings for centuries
- Casa de Juntas oval parliamentary chamber with its spectacular stained-glass dome depicting the Tree of Gernika
- 18th-century ancestor oak stump preserved under the neoclassical Pavilion of the Old Tree (built 1820)
- Free entry to one of the most symbolically important political and cultural sites in Basque history
- Parliament of Bizkaia still convenes ceremonially in the historic assembly hall
Tips for visiting
- Visit on a weekday morning to avoid the coach parties that typically arrive from mid-morning onward
- Combine with the Gernika Peace Museum, a 5-minute walk on Foru Plaza, to cover the full historical narrative of the 1937 bombing
- Travel by Euskotren from Bilbao's Atxuri station for a scenic 50-minute journey through the Urdaibai estuary biosphere reserve
- Guided tours in Spanish, Basque, and English are available at reception and cover the parliamentary history in depth
- Photography is permitted inside the Casa de Juntas chamber; respectful behaviour is expected during any active ceremonial sessions
Frequently asked questions
Is admission to the Casa de Juntas and the oak tree free?
Yes. Admission to both the parliamentary chamber and the oak tree courtyard is free. The site is open most days, though hours can vary by season; checking ahead is advisable outside summer months.
How long does a visit typically take?
Most visitors spend between 45 minutes and 1.5 hours, including the chamber, the stained-glass dome, the old oak stump pavilion, and the courtyard tree.
Is the site suitable for children?
Yes. The living oak tree and the colourful stained-glass dome are particularly engaging for children, and the site is flat and easily navigated.
Are English-language explanations available?
Interpretive panels in the chamber are provided in Basque, Spanish, and English. An English-language audio guide is also available at the entrance.