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 PortugueseCentre Region. The castle was part of the defensive line controlled by the Knights Templar, and a stronghold used during the Portuguese Reconquista.
Castles in Portugal were crucial components of the militaryacross history. The Portuguese learned the art of fortificationconstruction from the Romans and the Moors. The Romans, who ruled and colonized the territory of current-day Portugal for more than four centuries, built forts with high walls and strong towers to defend their populations. The Moors, who invaded the Iberian Peninsula in the year 711, brought new stonework and heavily fortified gates to the peninsula.