The funicular train of Artxanda takes you from the town center up to the Artxanda hill, surrounding Bilbao. Once you get out of the funicular (that as a public transport costs around a euro per trip), get to the left and walk for about three minutes. You will reach a mirador overlooking Bilbao. The views are spectacular, you cover the whole city, the sea, the airport and the mountains that embrace Bilbao. You also get a perfect view of the Guggenheim museum, the river and the Old Town.