Any discussion among Portuguese nationals always ends–and sometimes begins–in the 15th century. That is, back when Portugal ruled the seas with their caravals and their secret nautical data and charts. Back when such data and charts were as good as gold because they would lead you to the gold.
Wonderful photos and text! A recent trip to Lisbon and these very sites–the monument, the maps, the nautical museum’s model caravels–and the secrecy you describe– have inspired me to write a novel in which a woman crew member on a replica caravel celebrating the 15th c discoveries travels back in time and discovers there were other Portuguese explorers, forgotten by history, who bravely roamed the wild waves–every trace of their voyages and discoveries expunged–until now! Or as soon as I can write the novel!