Taking a short detour, the funicular railway that takes you up to Artxanda is well worth a trip. Find the entrance in the streets north of Zubizuri bridge and ride up to the top of another hill overlooking Bilbao. Artxanda is also an area renown for its restaurants, possibly with a more modern flavour, so go up for lunch and enjoy good food with excellent views. Near the station, actually on the road you can see in front of the train, is the best panoramic viewpoint of the whole of Bilbao, over the city and even out to the Bay of Biscay. If this photo were better definition you would be able to see above the driver's head the cathedral, Plaza Nueva and the ascensor but you can probably make out Parque Etxebarria on the left.