The Castillo del Príncipe (Castle of the Prince) is a military fort located in the Loma de Aróstegui, in Havana, Cuba.

The construction was in charge of the colonel of engineers the Navarrese Silvestre Abarca y Aznar, the same one who built the Fortress of San Carlos de La Cabaña in the bay.

It housed common and political prisoners, including José Martí's teacher, Rafael María de Mendive [es].

The castle has the shape of an irregular pentagon and has two bastions, two semi-bastions and a redan (V-shaped protrusion), further comprises deep trenches, mine galleries, warehouses, offices, a water cistern and a housing area large enough to accommodate a garrison of 1000 soldiers.

[citation needed] The Bay of Pigs: The Leaders' Story of Brigade 2506 (9780393331202): Johnson, Haynes: Books Castle del Príncipe