The castle of Almada is supposed to be of Arab origin, being referred to in the 12th century as “Hosnel-Madan” (fortress of the mine). Its location on the south bank of the Tagus, opposite the city of Lisbon, made it an important strategic point during the Reconquest period, being successively occupied and transformed.
In 1191, a Moorish invasion destroyed the castle. Only four years later it was taken over by D. Sancho I who ordered reconstruction works that continued under the reigns of D. Dinis and D. Fernando. In the 16th and 17th centuries it underwent changes to adapt to new military technologies, and after the 1755 earthquake it was rebuilt.
In 1825, after the Napoleonic Wars it was decommissioned, being refurbished in 1831, for the occasion of the Portuguese Civil War. Later, during the years 1865 and 1866, repairs were carried out under the Lisbon and Port defence plan of the Marquês de Sá da Bandeira where the Almada Fort played a major role in the line of defence of the south bank of the Tagus.
Protected by the river-side cliffs, it features ramparts, moats and protected firing points on the city side of Almada.
Currently, the castle of Almada is featureless/uninspiring and still occupied by Republican National Guard (GNR) with a military unit inside. In the surrounding area of the fortification there is a public garden with belvedere, the "Jardim do Castelo", from which you have magnificent views over Lisbon and the Tagus estuary.