Colón

Portobelo was, for over a century, one of the most consequential ports in the Spanish Americas — the harbour where Peru's silver, carried overland across the isthmus, was loaded onto galleons bound for Spain, and where periodic trade fairs briefly transformed the small town into one of the wealthiest places on the continent, its streets said to fill with merchants and treasure during the weeks a fleet was in port. That wealth made Portobelo a target as often as a triumph: pirates and privateers, most famously Henry Morgan in 1668, attacked and sacked the town repeatedly, prompting Spain to build the extensive stone fortifications — San Jerónimo, Santiago and San Fernando among them — whose ruins still ring the bay today, cannons still positioned in some of the batteries facing out to sea. UNESCO inscribed the fortifications as a World Heritage Site, and walking among the crumbling walls and rusted cannon, with the harbour still visible beyond them, gives a genuinely tangible sense of the wealth and danger that once defined this coast.

San Lorenzo Fort sits on a bluff at the mouth of the Chagres River, guarding the alternative inland route Spanish treasure convoys used to avoid crossing the isthmus entirely overland — river transport upstream, then a shorter overland leg, rather than the longer and more exposed land route Portobelo's own fair system otherwise relied on. Also UNESCO-listed alongside Portobelo, San Lorenzo sees far fewer visitors, its jungle-edged, more remote setting giving it a wilder, less manicured atmosphere than Portobelo's harbourside ruins — walls draped in creeping vegetation, howler monkeys sometimes audible from the surrounding forest, and sweeping views out over the river mouth to the Caribbean. The fort's more difficult access is part of what has kept it quieter, making it a rewarding stop for visitors who've already done Portobelo and want the same colonial-military history without the crowds.

The Agua Clara locks, the Caribbean-side component of the Panama Canal's 2016 Neopanamax expansion, have their own visitor centre here — generally quieter and less crowded than Miraflores on the Pacific side, with a viewing platform overlooking the modern, wider lock chambers built to accommodate today's largest container ships. Colón city itself, the provincial capital, was once a genuinely prosperous free-trade hub and remains home to one of the largest free-trade zones in the world by trade volume, a fact that surprises visitors who see comparatively little of that wealth reflected in the city's own streets today; most travellers pass through en route to Portobelo, San Lorenzo or the locks rather than lingering in the city itself.