The Canal du Midi was constructed by Pierre Paul Riquet and more than 12,000 workers between 1667 and 1681. The 240 km canal joined the Mediterranean Sea with the Atlantic Ocean, opening up a prosperous trade route. But, the Canal du Midi’s fame was short-lived. When the railway came to France just 150 years later in 1832, canal traffic declined. Today the Canal du Midi is a UNESCO World Heritage Site and tourist attraction, though still a hidden gem.