Fuerte de San Fernando & Batería de San José
On the southern tip of the Isla de Tierrabomba, at the entrance to the Bahía de Cartagena through the Bocachica strait, is Fuerte de San Fernando. On the opposite side of the strait is another fort, Batería de San José, and together they once guarded access to the bay. A heavy chain was strung between them to prevent surprise attacks in the 1700s.
Islas del Rosario
This archipelago, about 35km southwest of Cartagena, consists of 27 small coral islands, including some tiny islets. The archipelago is surrounded by coral reefs, where the color of the sea ranges from turquoise to purple. The whole area has been declared a national park, the Parque Nacional Natural (PNN) Corales del Rosario y San Bernardo.