Although it can be quite fusty for laymen, the Naval Museum will enthrall military historians. Constructed in the early 1600s, the original colonial wing housed the first Jesuit school in the Americas. The Republican (or Eastern) wing was added some 300 years later to house the Navy. The museum does a fine job (if you speak Spanish) of explaining Cartagena’s strategic importance as a port, as well as lingering over the exploits of Britain’s nefarious pirates. Along with an exhaustive display of antique naval instruments, maps, and dioramas, a series of intricate exhibits featuring miniature ships depict Cartagena’s most significant battles and invasions, as well as the engineering techniques used in the construction of Cartagena walls, bastions, and fortresses. For kids, there’s a hugely popular interactive submarine. Try to visit early morning; the museum has no air-conditioning.