 In Yucatan , Morgan confronts Sahin and the Ottomans searching for the Lake and destroys the Ottoman base . However the Spanish conquistador , Francisco Juan Delgado de Leon , captures Sahin and some other Ottoman soldiers before Morgan can . Morgan is then forced to fight and defeat the Spanish , who are attacking Morgan 's new allies , the Aztecs . After his battle to defend the Aztecs , Morgan realizes that Delgado and the Spanish were after the map to the Lake of the Moon disguised as the mosaic in the Aztecs ' town square . The mosaic shows the Lake of the Moon being in Florida . 
