Originally a Spanish fort, it was abandoned at an unknown time. Sometime before the year 1899, Hercule Fontaine made it the capital of his rebel movement.
Events of Red Dead Redemption 2
After rescuing Javier from Aguasdulces, and a group of Guarman workers near La Capilla, the Van der Linde gang rendezvous with Hercule at Cinco Torres. It is then that the Cuban army launches a ground invasion of the fort, while a large warship approaches. The gang and Hercule open fire on the enemy soldiers, and succeed in holding them off before the overwhelming numbers reach the fort. Dutch, Hercule and Arthur then charge out, and cut down the soldiers who have reached the fort. They then realize that the Cuban warship is within firing range of Cinco Torres, and Hercule and Arthur rush up to the cannon on top of the fort. Arthur mans the cannon, and brings down the warship, saving Cinco Torres.