For hundreds of years, sailing between the Pacific and Atlantic oceans meant navigating the perilous waters of Cape Horn at South America’s southern tip. So, European colonists came up with a solution: Build a canal connecting the two oceans at the Isthmus of Panama, a small strip of land between Central and SouthAmerica. Constructing it proved difficult, however, and after failed attempts by the French in the 19th century, the Americans took on the project. Over the span of 33 years, 25,000 workers built locks at each end of the isthmus, lifting ships 85 feet up to the man-made Gatun Lake, allowing them to move from one end to the other. In 1914, an American cargo and passenger ship, the SS Arcon, was the first to transit the canal. The Panama Canal’s history as one of the most impressive engineering achievements of all time is the highlight of these voyages, for sure, but fascinating ports and an easy pace add to their appeal. On a 15-day cruise (east or west bound) between November and April, guests sample South America’s Caribbean coast, Costa Rica and Panama's rainforests, and colonial cities of Mexico, with relaxing sea days in between. Most itineraries include the historic old town of Cartagena, Colombia, a UNESCO World Heritage site and a collage of color and charm, enhanced by light sea breezes and tropical aromas, and Puerto Caldera, Costa Rica, offering easy access to multiple national parks for active adventure. And Panama is more than just the canal—it is home to rainforests, mangrove wetlands and mountain cloud forests, with as many as 500 species of birds and 100species of mammals.