The Área Protegida San Lorenzo (www.sanlorenzo.org.pa ) is one of Panama ’s newest protected areas. Its 12,000 hectares include a former U.S. military base (Fort Sherman), the impressive ruins of the Spanish fort of San Lorenzo, and four types of forest, including mangroves and freshwater wetlands.
The United States left most of this forest standing, and with the departure of the military, all kinds of wildlife have returned even to formerly populated areas. The big question is what happens next.
Conflicting demands are being made on the area. On the one side are those who want to preserve this vital ecosystem, restricting its use as much as possible to ecotourism and scientific research. This area is a crucial link in the biological corridor that runs the length of Panama, especially since so much of the land to the east and west of it has already been deforested. That also makes it a linchpin in the even more important Mesoamerican Biological Corridor, which runs the entire length of Central America.
On the other side are those who see this entire region as prime real estate. Also, slash-and-burn farmers, hunters, and loggers began to invade the area after the departure of the U.S. military.
Still, it seems likely that those pushing for conservation will be at least partly successful. In the short term, only organized groups are being allowed into most of the protected area. That’s probably just as well for now, because visitors really wouldn’t want to wander around here by themselves.
Besides the usual hazards found in a tropical forest, there is unexploded ordnance in the area. The U.S. military conducted jungle-warfare training and had a firing range here. For more information on Área Protegida San Lorenzo, visit www.sanlorenzo.org.pa .
The ruins of Fuerte San Lorenzo (full name: Castillo de San Lorenzo el Real de Chagres) are impressive and surprisingly intact. They sit on the edge of a cliff with a commanding view of the Caribbean coast and the mouth of the Río Chagres , which the Spaniards built the fort to protect. The Welsh buccaneer Henry Morgan won a bloody battle here in 1671, destroying the then-wooden fort before crossing the isthmus to sack Panama City .
San Lorenzo was rebuilt as a strong stone fort in 1680, but the British admiral Edward Vernon still managed to destroy it in 1740. It was rebuilt yet again in 1768, with more fortifications added in 1779. These are the ruins visible today. The ruins, along with those at Portobelo , were declared a UNESCO World Heritage Site in 1980.
Note: Be careful wandering around the fort. There are few guard rails and it’s easy to walk right off a roof or a cliff. Supposedly at least one tourist has.
The entrance to the area is 12 kilometers past Gatún Locks  in the former U.S. military base of Fort Sherman; stay straight after crossing over the swing bridge at the locks. Fuerte San Lorenzo is another 11 kilometers up a rough but passable road. It’s a left turn past the entrance to Fort Sherman. On the way to Fort Sherman, look for a water-filled channel near the road. This is the French Cut, a remnant of the doomed French effort to build a sea-level canal.
Once-popular Shimmy Beach, to the right as one enters Sherman, is covered in trash washed up from Colón —not the best spot for a swim. The turnoff to San Lorenzo is on the left. It’s a 20-minute drive on a sometimes-rough road from here. Those without a four-wheel drive can ask about road conditions at the gate. The guard might possibly know.
From this point on the road is surrounded by beautiful rainforest. It’s easy to feel transported back in time and imagine conquistadors and pirates hacking their way through this jungle in their relentless pursuit of treasure. Follow the signs to the fort, which is where the road ends. Road conditions get fairly rough toward the end.