Bilbao, an industrial port city in northern Spain, is surrounded by green mountains. It’s the de facto capital of Basque Country, with a skyscraper-filled downtown. It’s famed for the Frank Gehry–designed Guggenheim Museum Bilbao, which sparked revitalization when it opened in 1997. The museum houses prominent modern and contemporary works, but it’s the curvy, titanium-clad building that receives the most attention.