The Montachique redoubt is in the Cabeço de Montachique Municipal Park. Its strategic objective was to defend the São Gião pass. In conjunction with the Moinho redoubt, it controlled the Royal Road from Mafra.
During the Peninsular Wars, also known as the French Invasions (1807 – 1810), the hamlet of Montachique was strategically placed because of its proximity to many other fortifications. For this reason, a livestock supply post for the Anglo-Portuguese troops was based here.