Palmela Castle, situated at 240 meters altitude in the Arrábida mountain range, dominates a unique landscape between the Tagus and Sado estuaries. With a history dating back to the Roman period, the castle was successively occupied by Visigoths, Muslims, and Christian forces during the Reconquest.

Palmela Castle, situated at 240 meters altitude in the Arrábida mountain range, dominates a unique landscape between the Tagus and Sado estuaries. With a history dating back to the Roman period, the castle was successively occupied by Visigoths, Muslims, and Christian forces during the Reconquest. Its defensive structure is developed in three lines of walls: the inner line, from the 12th-13th centuries, includes cylindrical towers and the Gothic keep; the middle line, from the 15th century, incorporates the church of Santiago and the convent; the outer line, from the 17th century, features bastions adapted for artillery.

Definitively conquered by King Afonso Henriques in 1147, the castle became the headquarters of the Order of Santiago in 1443. The successive architectural interventions reflect different historical periods: Roman circular towers, Arab square towers, Manueline fortifications, and adaptations for artillery defense.

Today, the castle houses the Municipal Museum, the Historic Inn, craft shops, and a restaurant. From its viewpoint, one can observe impressive panoramas over Setúbal, the Tróia peninsula, and the Lisbon coast.