The city's much-cherished subway system opened in 1995, and was designed by British architect Sir Norman Foster, winner of the 1999 Pritzker Architecture Prize and architect of Barcelona's 1992 Collserola Communications tower, and—more recently—the international terminal at Beijing Airport. Bilbao's first metro has become a source of great pride for bilbainos. Only a necessity when Bilbao began to spread up and down the Nervión estuary, the Bilbao subway now connects Bolueta, upstream from the Casco Viejo, with Plentzia, a run of 30 km (19 miles) and, in the other direction, with Basauri. The metro is invariably spotless, graffiti is scarce, and most of its passengers are well dressed and ride in a respectful silence. A fairly recent line runs down the left bank of the Nervión to Portugalete and Santurtzi.
Winner of the railway architecture Brunel Prize of 1996, the metro in general and the Sarriko station in particular were designated as the prizewinning elements. The Sarriko
station, the largest of all of the 23 stops, is popularly known as El Fosterazo (the Big Foster); the others are Fosteritos (Little Fosters). The most spectacular are segmented glass tubes curving up from underground, such as those at Plaza Circular and Plaza Moyúa, widely thought to resemble transparent snails.