The Fort Santa Susana also referred to as the Fort São Lourenço, is located south of the beach São Lourenço, in the parish of Santo Isidoro in the municipality of Mafra in the Lisbon District of Portugal. The fort was built during the Portuguese Restoration War (1640-68) following the instructions of the Council of War set up by King John IV. It was one of many coastal forts designed to protect against both Spanish invasion and pirates. Supervision of the construction was the responsibility of António Luís de Meneses, 1st Marquis of Marialva and 3rd Count of Cantanhede.