Castillo San Felipe de Barajas, Cartagena, Bolivar, Colombia
Hulking strategically at one edge of the historic city of Cartagena, this behemoth of a structure was constructed to deter the likes of notorious pirates Drake and Hawkins and protect Spanish imperial interests in the region. In 1980 the castle's complex system of tunnels, ramparts and fortifications was declared a UNESCO World Heritage site. Visit in the morning or in the late afternoon to avoid the blaze of the near equatorial sun and allow time to marvel at the thickness of these impenetrable walls, which were built over 200 fraught years. In order to understand the full history of this castle, multilingual guides can be found at the entrance or contacted via your hotel.