With a spectacular setting on a promontory above the Caribbean and overlooking the mouth of the Río Chagres, Fort San Lorenzo is the most impressive Spanish fortification still standing in Panama. Until the construction of the railway, the Chagres was the main cargo route across the isthmus to Panama City, and thus of enormous strategic importance to Spain. The first fortifications to protect the entrance to the river were built here in 1595, but the fort was taken by Francis Drake in 1596 and, though heavily reinforced, fell again to Henry Morgan’s pirates in December 1670. Morgan then proceeded up the Chagres and across the isthmus to ransack Panama City. The fortifications that remain today were built in the mid-eighteenth century. The site as a whole is imposing, with a moat surrounding stout stone walls and great cannons looking out from the embrasures, all of it kept in isolation by the dense rainforest all around.