Cartagena is an important port on the Caribbean Sea. In the city, on top of a hill, is the Castillo San Felipe de Barajas, a castle built in the 16th and 17th centuries by the Spaniards. The city was often attacked by pirates and other invaders attempting to capture treasure going to Spain. To defend Cartagena from these assaults, a wall was built around the castle. (GETTY IMAGES)