La Fortaleza (English: "the fortress"), also known as the Palacio de Santa Catalina[3] (Saint Catherine's Palace), is the official residence and workplace of the governor of Puerto Rico.

La fortaleza, alongside El Morro, San Cristóbal, El Cañuelo, and other forts part of the Walls of Old San Juan, protected strategically and militarily important Puerto Rico, or La Llave de las Indias (The Key to the Indies),[5] from invasion by competing world powers and harassment by privateers and pirates during the Age of Sail.

Starting in 1529, Governor La Gama petitioned the emperor on the need to build defensive fortifications "because the island's defenseless condition caused the people to emigrate."

[8][9] Since the 16th century, La Fortaleza has acted as the residence of the Governor of Puerto Rico, making it the oldest executive mansion in continuous use in the Americas.

La Fortaleza has been captured three times by foreign powers: In 1834, Colonel George Dawson Flinter described the fortress of Santa Catalina as having a chapel, stables, cistern, and an east wing with spacious apartments.

The paintings exhibited at La Fortaleza are on loan from the Institute of Puerto Rican Historical Culture and are changed according to the taste of the ruler of the day.

U.S. Presidents who have visited La Fortaleza, include Herbert Hoover in 1931, Harry S. Truman in 1948, John F. Kennedy in 1961, Barack Obama in 2011, and Bill Clinton in 2013.

In 2011, Puerto Rican author Giannina Braschi wrote the dramatic novel United States of Banana, featuring climactic scenes of revolution at La Fortaleza.