Amorebieta

In January 2019, a third-tier side beat Athletic Bilbao 3–2 in the Copa del Rey.

The squad was made up entirely of Basque-born players and ran on the smallest budget of anyone in the competition. The goalkeeper through that run, Mikel Saizar, worked as a pastry chef.

Promotion brought a problem. Second-tier licensing demands a ground of at least 5,000 seats, and Urko has 3,000. So the club moved its home fixtures to San Mamés in Bilbao — a stadium of roughly 53,000, borrowed for two separate spells, in 2021–22 and again in 2023–24, after Amorebieta went back up as champions of Group II of the Primera Federación.

Both spells ended in relegation. The first cost the club Gorka Guruzeta, who finished the 2021–22 season as the division's leading scorer with 13 goals and left for Athletic Bilbao.

The season after it, Amorebieta reached the semi-finals of the Spanish Amateur Championship and drew 2–2 away at Real Madrid Castilla before losing the return.

The fixture that carries the most weight is against Sestao River — the Left Bank Derby. Barakaldo CF counts too.

So does the ground: Urko sits in Amorebieta-Etxano, in Biscay, and on the days the club is not renting somebody else's stadium, that is where it plays.