Fort of King Luís I - Credit: Wikimedia Commons
The Fort of King Luís I (Forte D. Luís I), also referred to as the Fort of Caxias (Forte de Caxias) and the Fort-prison of Caxias (Forte-prisão de Caxias), is located in the parish of Caxias, in the municipality of Oeiras in the Lisbon district of Portugal. It presently functions as a prison. Read more on Wikipedia
Source: en.wikipedia.org