The small fort of San Juan de la Cruz, better known today as El Cañuelo, was the smallest component of the harbor defense system, built on a tiny islet.
The cannon at El Cañuelo helped El Morro block the harbor entrance with a deadly crossfire. This little square redoubt also watched the mouth of the Bayamón River, an important passageway for supplies from the interior of
Puerto Rico. At one time, an enormous chain was kept ready to be stretched between El Cañuelo and El Morro in order to physically barricade the channel. First built of wood, El Cañuelo was in the thick of the fighting during the 1625 Dutch attack, and burned to ashes. A new stone fort was built by the Spaniards in the 1670's.
