The castle was severely damaged by the great earthquake of 1755. I mean, Lisbon has experienced many earthquakes, but that of 1755 was the strongest by far, and a tsunami and big fire followed it, thus damaging the city
As I walked in the castle ground, I imagined Vasco de Gama walking there, warmly and generously welcomed as a hero. He came back home from a long trip, and was honored for discovering the maritime route to India in 1498. They had some party for him in that castle.
He found the key to imperial colonialism. And he was cheered for it.