 In 1762, Antonio de Arebalo published his Defense Plan, the Report on the estate of defense on the avenues of Cartagena de Indias.This engineer continued the work to make Cartagena impregnable, including the construction from 1771 to 1778, of a 3400 yards long underwater jetty across the Bocagrande called the "Escollera".Arebalo had earlier completed "San Fernando", and the fort-battery of "San Jose" in 1759, then added "El Angel San Rafael" on El Horno hill as added protection across the Bocachica.