Fortín San Juan de la Cruz (Fort Saint John of the Cross), most commonly known as El Cañuelo, was built on Isla de Cabras in the Palo Seco barrio of the municipality of Toa Baja, at the western end of the entrance to San Juan Bay, in Puerto Rico.

The original fort built on this site in the late 1500s was made of wood; it burned to the ground in 1625 during a Dutch attack.

[citation needed] The square fort is about 80 feet (24 m) per side, with one guerite (garita in Spanish).

El Cañuelo Island was originally a rocky islet completely surrounded by water and accessible only by boat.

The site features fabulous views of Boca Vieja Cove to the west and San Juan Bay to the east.