Panama Canal

The canal crosses the narrow Isthmus of Panama for about 80 kilometres, creating a shipping passage between the Atlantic and Pacific. It is not a sea-level cut: ships travel through locks that act as water lifts. The locks raise vessels from either ocean to Gatun Lake, around 26 metres above sea level, and lower them again at the opposite end. The principal lock sites are Gatún on the Atlantic side and Pedro Miguel and Miraflores on the Pacific side. Water from Gatun Lake flows by gravity into the lock chambers.

The lake and the excavated channel through Panama's central mountain range form much of the route. The Culebra Cut, an approximately 13.7-kilometre passage excavated through rock and limestone, is a narrow section of the canal. This design lets ships cross the continental divide without building a level trench all the way through the isthmus, but it also makes operation dependent on the freshwater used by the locks.

A French company led by Ferdinand de Lesseps began excavating in Panama in 1880, but the effort failed after years of severe disease, deaths and financial difficulty. The United States later selected the Panama route and negotiated with Colombia, which then governed the province. After Panama declared independence from Colombia in 1903, the new republic and the United States concluded the Hay–Bunau-Varilla Treaty. The agreement granted the United States extensive rights over a Canal Zone; the way the treaty was negotiated and the continuing U.S. presence became lasting sources of dispute between the two countries.

The United States built the canal, which opened in 1914. U.S. control of the Canal Zone and the waterway remained contentious. In 1977, Panamanian leader Omar Torrijos and U.S. President Jimmy Carter signed two treaties: one addressed the canal's permanent neutrality, and the other set a timetable for transferring control to Panama. Panama took full control of the canal on December 31, 1999.

A third set of locks was built to expand the canal's capacity and accommodate ships too large for the original locks. The expanded lane was inaugurated on June 26, 2016. The Panama Canal Authority, an autonomous agency of the Panamanian government, administers, operates and maintains the waterway. Its role includes managing the lock system and the freshwater resources needed for transits. The canal remains an international route, governed by arrangements that provide for its neutral use by vessels of all nations.