Prince Castle. It was built in 1767 and completed in 1779, was named in honor of Prince Charles, son of Carlos III. It was located on one of the hills surrounding Havana, designed by military engineers Silvestre Abarca, Agustín Crame and Luis Huet. Now surrounded by urban growth, he closed with its contemporary Castle Santo Domingo de Atarés rushing defensive ring, and formed a defensive triangle of the city, with the Fortress of San Carlos de La Cabaña. It is a condensed example of fortification in advance of his time.