San Felipe de Barajas is a military fortress in the City of Cartagena de Indias built by the Spaniards during the Colonial time in present - day Colombia. It was the greatest and strongest fortress ever built by the Spaniards in any of their colonies in the American continent. The construction started in 1536 under the name of San Lazaro Castle; in 1657 an extensive enlargement was undertaken. It was built on top of the San Lázaro Hill. From there any attempt to storm the city either by land or moving through the Bay of Cartagena in the Caribbean Sea could be defended.