We did not get to the top. Instead, my family hid inside one of the small fort towers on the first floor and our view was captured by the attached picture.
Belém Tower officially the Tower of Saint Vincent is a 16th-century fortification located in Lisbon that served as a point of embarkation and disembarkation for Portuguese explorers and as a ceremonial gateway to Lisbon. It was built during the height of the Portuguese Renaissance, and is a prominent example of the Portuguese Manueline style, but it also incorporates hints of other architectural styles. The structure was built from lioz limestone and is composed of a bastion and a 30-metre four-storey tower. (Wikipedia)