THE CANAL CLIMBS the rises of the western Midi by twos and threes, the locks carrying us upward to the Lauragais plain. To the north are the Black Mountains, source of the water that fills the reservoir built by Pierre-Paul Riquet—water that feeds the 60 kilometer long “creek” that feeds our canal. The Seuil de Nauroze, or the threshold, is where this collected mountain rain enters the Canal du Midi. A stone obelisk stands as a monument to Riquet's triumph. Classified as a UNESCO world heritage site, the Canal du Midi now runs downstream in both directions—toward the Atlantic at écluse l'Ocean and toward the Mediterranean at lock La Mediterranean. This milestone is called “the parting of the waters.”