Workers start pouring concrete for the Panama Canal.

The Panama Canal is an artificial 82-kilometer (51-mile) waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a conduit for maritime trade between the Atlantic Ocean and the Pacific Ocean. Locks at each end lift ships up to Gatun Lake, an artificial fresh water lake 26 meters (85 ft) above sea level, created by damming the Chagres River and Lake Alajuela to reduce the amount of excavation work required for the canal. Locks then lower the ships at the other end. The original locks are 33.5 meters (110 ft) wide and allow the passage of Panamax ships. A third, wider lane of locks was constructed between September 2007 and May 2016. The expanded waterway began commercial operation on 26 June 2016. The new locks allow for the transit of larger, Neopanamax ships. An average of 200,000,000 litres of fresh water is used in a single passing of a ship. The canal is threatened by low water levels during droughts.