The Forte de Santa Maria da Arrábida, also known as Fort Nossa Senhora da Arrábida, is an 18th century bastion castle built during the Portuguese Restoration War. Located at the foot of Arrábida Mountain range in Portugal, it serves as a gateway to the Sado River. It stands in a dominant position overlooking Portinho da Arrábida and has been through many reincarnations since its construction; from a military structure to a restaurant and inn over the years, it currently houses the Luís de Saldanha Oceanographic Museum. Its chapel features an impressive 17th century image of Our Lady carved out of lioz stone, making it a place of pilgrimage for visitors. The fort has since become part of the Arrábida Natural Park, with events such as guided tours and small shops to explore.