Belém Tower (Portuguese: Torre de Belém, pronounced: [ˈtoʁ(ɨ) dɨ bɨˈlɐ̃ȷ̃]) or the Tower of St Vincent[1] is a fortified tower located in the civil parish of Santa Maria de Belém in the municipality of Lisbon, Portugal. It is a UNESCO World Heritage Site (along with the nearby Jerónimos Monastery)[2] because of the significant role it played in the Portuguese maritime discoveries of the era of the Age of Discoveries.[3] The tower was commissioned by King John II to be part of a defense system at the mouth of the Tagus river and a ceremonial gateway to Lisbon.[3]