The Castle of Almourol is a medieval castle, located on a small islet in the middle of the Tagus River, in the civil parish of Praia do Ribatejo, 4 kilometres (2.5 mi) from the municipal seat of Vila Nova da Barquinha, in the Portuguese Centre Region. The castle was part of the defensive line controlled by the Knights Templar, and a stronghold used during the Portuguese Reconquista.
It is believed that the castle was constructed on the site of a primitive Lusitanian castro that was later conquered by the Romans during the 1st century B.C.E. It was later remodelled by successive invading forces, including the Alans, Visigoths and Moors, although it is unclear when the actual castle was established. In excavations carried out in the interior and exterior enclosures, various vestiges of Roman occupation were discovered, that included coins, millennium markers and Roman foundations, while medieval remnants such as medallions and two marble columns were also discovered in the castle's vicinity.
Almourol is a small islet on the Tagus river, Portugal. The Castle of Almourol, a national monument, is located there.
Coordinates: 39°27′43″N 8°23′06″W / 39.462°N 8.385°W / 39.462; -8.385