The Fort of Archeira is located in the municipality of Torres Vedras, in the Lisbon District of Portugal. It is also today known as the Furadouro Redoubt and was called the “Cheira” at the time of construction. Construction began in 1810 as part of the first of the three Lines of Torres Vedras, which were defensive lines to protect the Portuguese capital Lisbon from invasion by the French during the Peninsular War (1807–14) or, in the event of defeat, to protect the embarkation of a retreating British Army.