Actually declared a "wonder of the world" by UNESCO in 1996, the Midi Canal was built in the 17th century by Peirre-Paul Riquet. It basically remains virtually the same as far as lock design and function. Its purpose was to connect the Atlantic Ocean to the Mediterranean Sea by way of the foot of the Pyrenees mountains. There are actually three sections to be navigated; The Canal du Midi (70 locks); the Lateral canal to the Garonne (53 locks) and the Garoone (2 locks). The entire canal covers a length of 496 km.
The Canal took over 20 years to build and 12,000 men to dig what was to become an actual work of art. The Canal was opened in 1681, a year after its founder's death. The king, queen, and prince of France came from Versailles and actually toured the length, delighted by the enchanting turns and twists taken through the lovely Languedoc region. You can recreate this tour today by traveling on an inexpensive yet comfortable "barge" or longboat which holds parties of 6-8 comfortably. Little skill is required to operate and navigate and captains can be hired for the truly squeamish.