Stretching 80km from Panama City in the south to Colón in the north, the Panama Canal is a work of mesmerizing engineering brilliance. One of the largest and most ambitious human endeavours, the waterway allows massive vessels – which otherwise would have to travel all the way south around Cape Horn – to traverse the isthmus in less than one day. East of the canal spreads the rainforest of Parque Nacional Soberanía, the greatest possible contrast to its mechanical might. Delve into the park’s humming, humid atmosphere on one of its many accessible pathways, and you’ll discover unparalleled biodiversity. Colón, at the Atlantic entrance to the canal, and only a boat or train or bus ride away from Panama City, seems like a different world from the capital – a brief tour of the poverty-stricken city from the safety of a taxi leaves you in no doubt about the canal’s socioeconomic importance, and the depth of Panama’s social inequalities. Some 45km northeast of Colón lies another port – Portobelo – whose glory days are even more distant. Its riches once proved irresistible to such pirates as Sir Francis Drake and Henry Morgan, and its once-mighty fortifications are now atmospheric ruins.