In 1601 Fuerte San Felipe and Fuerte San Diego were built near the mouth of the bay but were subsequently destroyed by Admiral Vernon in 1739. Fuerte San Fernando was built over the ruins in 1760, with one battery of 14 cannons and one of six. American engineers dismantled much of the fort at the start of the 20th century, using the stones from the walls to create the breakwater protecting the northern end of the Panama Canal.
Boats can be hired from the water’s edge (US$5 per person round trip) to bring you across the bay to the fort.