Portugalete is a small town on the left bank of the Nervión estuary, about 14 kilometres downstream from Bilbao. Its star attraction is the Vizcaya Bridge (Puente Colgante), the world's oldest transporter bridge, built in 1893 and now a UNESCO World Heritage Site. The bridge carries a gondola platform across the river to Getxo, suspended from a high iron framework — you can ride the gondola across for a couple of euros, or pay a bit more to walk across the upper walkway for panoramic views of the estuary and the Cantabrian coast.
The old town climbs steeply from the waterfront, with narrow streets, iron balconies, and the medieval Basilica de Santa María. The Nervión Promenade is pleasant for a stroll, and there are several good pintxo bars along the main street. Portugalete is easy to reach on the Bilbao metro (Line 2) and makes a worthwhile half-day trip from the city.