Commercial and political rivalries in the Caribbean region in the 17th century resulted in the construction of this massive series of fortifications on a rocky promontory, built to protect the important port of Santiago. This intricate complex of forts, magazines, bastions and batteries is the most complete, best-preserved example of Spanish-American military architecture, based on Italian and Renaissance design principles.

Castle of San Pedro de la Roca and its associated defensive works are of exceptional value because they constitute the largest and most comprehensive example of the principles of Renaissance military engineering adapted to the requirements of European colonial powers in the Caribbean.