Colón is a Panamanian city and sea port beside the Caribbean Sea, lying near the Atlanticentrance to the Panama Canal. It is the capital of Panama's Colón Province and has traditionally been known as Panama'ssecond city. Originally, it was located entirely on Manzanillo Island, surrounded by Limon Bay, Manzanillo Bay and the Folks River, but, since the disestablishment of the Panama Canal Zone, the city's limits have been redefined to include Fort Gulick, a former U.S. Army base, as well the former Canal Zone towns of Cristobal, Margarita and Coco Solo.