It is part of the second line of defense and was finished in 1760. It is located at the entrance of the Monumental City and it is almost intact with cannons and all.

It was designed by Antonelli in 1586, and destroyed by Sir Francis Drake, an English pirate, in 1597. It was rebuilt and later attacked again, this time by William Parker in 1602. Today the ruins of its walls can be seen at the entrance of Portobelo Bay.