The Castle of San Lorenzo stands on a cliff at the mouth of the Chagres River, on the Caribbean coast of Panama, and it was built to stop pirates. Gold and silver came across the isthmus on the Camino Real and the river, and this stone fort guarded the river mouth from the sea. Construction began in the late sixteenth century, and the fort, with its ditch, ramparts and cannon, was a serious piece of military engineering. It did not hold forever. In 1671 Henry Morgan and a force of buccaneers took it after a fierce fight in which the Spanish defenders resisted until their thatched roofs caught fire. Morgan went on to sack Panama City.
The place is lovely and wild. From the top of the cliff you look out over the sea on one side and the brown, slow-moving Chagres on the other, with dense jungle spreading in every direction. Waves crash on the rocks below, and the old walls are green with moss and creepers. A fine, damp smell hangs over everything. The Chagres is the river that feeds Gatun Lake, and thus the Panama Canal, so the water that floats the ships begins here.
The road to the fort is half the pleasure. From Colon you cross the canal at the Gatun Locks, then follow a narrow road through the former Canal Zone, past the old American base of Fort Sherman, now partly returned to the jungle. The road passes under dense canopy, with barracks and old buildings half hidden in the trees. Bends are tight and the surface is rough, with roots and potholes. A few vendors sell cold drinks and fruit near the fort. In the wet season, between May and December, the road is muddy and visibility is poor, and in the dry months it is dustier but easier.
Birdwatchers will find plenty to look at, with trogons, motmots and tanagers around the entrance. Monkeys call from the trees, and the occasional crocodile lies on the river bank. Be careful of the cliffs, since there are few railings. Colon, eleven kilometres away, has fuel and basic food, though conditions there are rough. Bring water, insect repellent and a rain jacket, and give yourself a morning here rather than an hour.