Fuerte Monte Arnotegi crowns the 426-meter summit of Monte Arnotegi, a prominent peak visible from central Bilbao. This modest 19th-century bastion was constructed during the Carlist Wars and remains integral to the local landscape. The fort's location offers commanding panoramic views across Bilbao and the Nervión estuary, making it a destination for hikers seeking both historical significance and natural scenery. The surrounding area includes four forest parks that form part of Bilbao's Green Belt, preserving the region's natural environment around this historic military structure.