This massive stone structure was built in 1919 as a continuation of Getxo's defensive wall. It's an impressive sight, complete with columns and a balustraded terrace, though it's in a bad state of decay. Long-term restoration, however, is underway. And while it's not open to the public, free one-hour guided visits in Basque and Spanish are offered throughout the year, with some English-language tours in August.
Opposite the gallery is Bilbao's first lighthouse, known as the Estacíon de Salvamento de Náufragos.