The Canal du Midi is a 17th-century engineering masterpiece connecting the Atlantic to the Mediterranean over 240 kilometers. Designed by Pierre-Paul Riquet and taking 14 years to build (1667-1681). It is a UNESCO World Heritage Site lined with shady plane trees. In Carcassonne, the Port du Canal offers a departure point for boat cruises and boat rentals. Walking and cycling paths run along the banks. No license needed for boat rental.