With an altitude of 451 m, Mount Serantes is an excellent natural viewing balcony over the El Abra Bay and the coast.
It is easily accessible and is just 20 minutes from Bilbao.
Along with its spectacular views, Mount Serantes offers cycle paths, guided tours and workshops for anyone who wishes to learn about biodiversity, plus visits to the fortifications, which have been declared a sight of historic and cultural interest.
Mount Serantes stands at the mouth of the Bilbao river estuary on its left bank, overlooking the port of Bilbao.
It can be seen from all over the area, and the views of Greater Bilbao from its peak are excellent.
It is surrounded by a major hub of industry and mining, which has long been a driving force for the economy of Bizkaia.
Even so, it is a major natural area, and its accessibility makes it the perfect spot to enjoy nature just a few steps from the centre of Santurtzi.
Mount Serantes makes a perfect lookout point over the southern Bay of Biscay coast.
Its strategic location overlooking the El Abra Bay and the approaches to the Bilbao river estuary have led to a number of military facilities being built on its peak and slopes.
These fortifications comprise two main parts: the Serantes Fort and the guard tower on the hilltop, built at the time of the 19th century Carlist Wars: conflicts between rival claimants to the throne, with the Carlists, who supported the traditional monarchy, the rights of the church and the local codes of law on the one hand and the liberals, who wanted far-reaching political reforms to introduce a constitutional, parliamentary system of government, on the other.
The guard tower, completed in 1881, was built to hold off any attempted siege by Carlist forces.
It is built in a square design using dressed stone blocks, and features two levels plus the rooftop, which served as a lookout point and was flanked by sentry turrets.
From the top a watch could be kept on both banks of the Nervión River and the surrounding hills.
It was restored in 2020 and is now open to visitors at weekends.
The fort was built in 1882 as part of a programme to reorganise the defences on the river estuary outside Bilbao.
It takes the form of an irregular pentagon, with a surface area of around 8500 m2.
Gun batteries were later set up when the mysterious explosion of the US battleship Maine in the Bay of Havana during the Cuban war of independence on 16 February 1898 led to the outbreak of war between the USA and Spain on 25 April that same year.
Spain’s armed forces feared that the Americans might try to invade the Spanish mainland, so they fortified much of the Bay of Biscay coast, including the naturally sheltered areas at the mouth of the Nervión such as Mount Serantes, Punta Lucero and La Galea.
In the years between the two world wars these facilities were moved, as their proximity to towns was thought to pose a danger in case of attack.