One of the most fascinating places to visit in Cartagena is Castillo San Felipe de Barajas. It was originally built in 1536 and is the strongest fort ever constructed by the Spanish anywhere in the world. It’s included in the UNESCO World Heritage listing for Cartagena.
Originally known as Castillo de San Lázaro, it was built in a triangular shape with eight batteries. It was expanded in 1657 and 1753, and later renamed after King Felipe IV of Spain.
The fortress is incredibly large and completely unlike any other fortress I’ve ever visited. There doesn’t seem to be much of a plan to it which made it more ingenious and perplexing. I would recommend a guided or audio tour to understand the reasoning behind the design.
The defense system after the expansion of the fortress made it impossible to capture. Each battery and parapet protected one another, which means the entire defense system must be defeated just to take one battery. In addition, extreme heat, humidity, and the threat of malaria from the mosquitos in the swamps near the castle made the conditions for both attacking forces (and Spanish soldiers) unbearable.
The complex system of tunnels, many of which have yet to be excavated, made it easy to hear the footsteps of enemies and for communication between Spanish soldiers.
Visiting Castillo San Felipe
Admission costs COP$25,000 for adults and COP$10,500 for children (as of June 2017). An audio tour costs COP$15,000, and a professional guide can also be hired. Give yourself a good hour and a half to two hours if you get the audio guide and don’t forget to bring plenty of water. The fortress is about a 20 to 30 minute walk from the old city but only a short taxi ride. It can also be visited on a chiva tour.
You can get a good view of the size of the fortress from the walls at Getsemaní.