Fort of Ameixoeira
Fort of Ameixoeira, also known as Forte da Ameixoeira or the King Carlos I Fort, is in the Ameixoeira area of Lisbon, Portugal. It is now the headquarters of Portugal’s Security and Intelligence Service (SIS). The fort was built as part of Campo Entrincheirado, a ring of defenses to protect Lisbon around the end of the 19th and start of the 20th century. Plans for a fort began in 1875, but construction was slow and finished in December 1901; lighting work followed in 1906. It was named after King Carlos I. The fort originally covered about 73,900 m2, but a new road reduced its covered area to 19,019 m2. On 11 August 1924 it was attacked during a failed coup by supporters of Manuel Gomes da Costa.
After World War I, fixed defense became outdated, and the forts were repurposed. Ameixoeira’s 88 storerooms were used as ammunition depots. On 28 September 1943 one storeroom exploded, killing six soldiers and destroying the south wing; the exact cause is unknown. Reconstruction began in 1950, with improvements to the north wing and modern utilities installed. It then served as a warehouse until 1989, after which it fell into decay. In the late 20th century, cultural ministries considered using it for museum storage, but in 2006 it was assigned to the Intelligence Services, becoming SIS headquarters.
This page was last edited on 3 February 2026, at 00:01 (CET).