Fort of Nossa Senhora das Mercês de Catalazete - Credit: Wikimedia Commons
The Fort of Nossa Senhora das Mercês de Catalazete, also known as the Fort of Catalazete, is located on the right bank of the River Tagus estuary in the municipality of Oeiras in the Lisbon District of Portugal. The fort dates back to 1762, when a small battery was erected on a site between the Fort of São Julião da Barra and the Fort of Santo Amaro do Areeiro, with the purpose of strengthening the defence provided by those two forts. Read more on Wikipedia
Source: en.wikipedia.org