Complex sentence: Built in 1521 it served as the first fortification of the San Juan islet and residence for Juan Ponce de León and his family and also his cousins, although de Leon died in an expedition to Florida without ever getting to occupy the structure.
Split into simpler sentences: Built in 1521, it served as the first fortification of the San Juan islet. It was the residence for Juan Ponce de León and his family, and also his cousins, although de Leon died in an expedition to Florida without ever getting to occupy the structure.