Here are 25 interesting facts about Bilbao:

1. Bilbao is the largest city in the Basque Country region of Spain and serves as its economic and cultural center.

2. The city is known for its remarkable transformation from an industrial hub to a vibrant, modern metropolis.

3. Bilbao is home to the iconic Guggenheim Museum Bilbao, designed by architect Frank Gehry. The museum is a masterpiece of contemporary architecture and a major tourist attraction.

4. The city's symbol, La Salve Bridge, is a unique architectural feat that spans the Nervión River and provides stunning views of the Guggenheim Museum.

5. Bilbao's Old Town, known as Casco Viejo, features narrow medieval streets, charming squares, and historic buildings.
6. The Zubizuri Bridge, also called the "White Bridge," is a pedestrian bridge designed by Santiago Calatrava. Its stunning design has made it one of Bilbao's most recognizable landmarks.

7. Bilbao has a strong culinary tradition, and pintxos (Basque-style tapas) are a popular local dish. The city is renowned for its excellent food scene.

8. Athletic Club Bilbao, one of Spain's oldest football clubs, is based in Bilbao. The team has a policy of only fielding players from the Basque Country or those trained in its football academies.

9. The city hosts the Bilbao BBK Live music festival, which attracts renowned international artists and takes place on a picturesque hillside near Bilbao.

10. Bilbao has its own language, Basque (Euskara), which is distinct from Spanish and one of the oldest languages in Europe.

11. The University of Deusto, founded in 1886, is one of Spain's most prestigious universities and is located in Bilbao.

12. Bilbao's metro system is known for its unique station designs created by various architects, including Sir Norman Foster and Sir Richard Rogers.

13. The city's main avenue, Gran Vía, is lined with elegant buildings and serves as a vibrant commercial and cultural hub.

14. Bilbao is surrounded by beautiful natural landscapes, including the nearby mountains, beaches, and the UNESCO-listed Urdaibai Biosphere Reserve.

15. The city's soccer stadium, San Mamés Stadium, is known as "La Catedral" due to its impressive architecture and passionate football atmosphere.

16. Bilbao's climate is influenced by its proximity to the Bay of Biscay, resulting in mild winters and moderate summers.

17. The Basque Museum showcases the region's rich history, culture, and traditions, offering visitors insights into Basque heritage.

18. Bilbao has its own annual festival, Aste Nagusia, which translates to "Big Week" in Basque. It is a week-long celebration featuring traditional music, dancing, and fireworks.

19. The city's transportation system includes a funicular railway, the Artxanda Funicular, which connects the city center with Mount Artxanda, offering panoramic views of Bilbao.

20. Bilbao has a strong maritime tradition, and the Maritime Museum showcases the city's historical connection to the sea.

21. The Euskalduna Palace, a contemporary architectural masterpiece, is a multipurpose venue that hosts conferences, concerts, and cultural events.

22. The Basque region is known for its strong sense of identity and its pursuit of cultural and political autonomy within Spain.

23. Bilbao's industrial past is evident in areas such as Zorrozaurre, which is undergoing a large-scale urban renewal project to transform former industrial land into a sustainable neighborhood.

24. The city's annual international film festival, Zinemaldia, attracts renowned filmmakers and showcases a wide range of international films.

25. This city is famous for its cuisines. Such unique items include sandwiches made in baguette bread, locally known as 'bocadillos', and omelets with potatoes that are locally known as 'tortilla Espanola.