The Gran Vía de Don Diego López de Haro is Bilbao's main boulevard — a wide, tree-lined avenue cutting through the Ensanche (new town extension) with grand 19th-century commercial buildings, upmarket shops, and department stores. The street is named for the 13th-century lord who founded the city, and it runs from the elliptical Moyúa square past the Arriaga Theatre and down to the old town.
The Ensanche neighbourhood around the Gran Vía has a different character from the Casco Viejo: broader streets, taller buildings, and a more formal urban atmosphere. It is worth walking for the architecture — particularly around Moyúa square, where the Chavarri Palace and the Art Nouveau Campos Elíseos Theatre are among the finest buildings in the city.