Where life slips into a lower gear and scenes of southern France slip by like a magic lantern: drowsy villages, riverside markets, fields of corn, lavender, poppies and sunflowers.

Stretching for 150 miles between rosy-red Toulouse and the southern town of Sète, the Canal du Midi is the queen of French waterways. Commissioned by Louis XIV in 1666, built by the engineer Pierre-Paul Riquet, and listed by Unesco since 1996, it is the oldest working canal in the world. Along with the Garonne, it forms part of the Canal des Deux Mers, which allows boats an uninterrupted passage all the way from the Atlantic to the Mediterranean.

For centuries the canal was an important thoroughfare, for boats ferrying coal, stone, timber and other industrial goods, but its commercial importance waned following the arrival of the railways in the mid-19th Century. These days it is the preserve of pleasure-barges and narrow boats, many of which have been painstakingly restored by their owners. At a speed of just five miles per hour, life shifts into a slower gear, and snapshots of southern France slip by like a magic lantern: drowsy villages, riverside markets, fields of corn, lavender, poppies and sunflowers.

"It feels a bit like we're on a permanent holiday," smiles Marie Verguez, now in her fourth season on her narrowboat, La Péniche Soléïado. "There's a very close community on the canal. We're all rather alternative characters and we all enjoy being close to nature. Living on the water, you're forced to listen to the rhythm of the seasons."

More than 320 structures are dotted along the Canal du Midi, including 40 aqueducts, 90 locks, many feeder canals and France's first subterranean water tunnel. Famously, at Fonséranes, a series of seven staircase locks allows the canal to drop 21.5 metres, while at Agde, a round lock allows boats to turn around and choose one of three exits. At its southern end, the canal cuts past the turrets of Carcassonne before meandering through the Petite Camargue, a natural wetland frequented by flamingos, herons, ibis and wild horses.

"There's something magical about being on the water," muses Marie. "Life moves at a slower pace. It encourages contemplation and inner peace. You discover a freedom that you could never find living in the city." She turns her gaze back to the canal, as the hazy evening sun filters through the trees and the gentle putt-putt of the boat's engine echoes across the water.

Where to stay
Marie's bottle-green canal boat offers three rooms and two cabins that make the perfect family getaway on the Canal du Midi. It is the epitome of bohemian canal living: potted plants and wooden loungers on the deck, home-cooked meals in the wood-panelled galley, and regular cruises along the river in the company of Marie and partner Pascal (from £50).

Where to eat
Afternoon teas and ice creams are served on La Maison de la Violette, a converted barge moored opposite Gare Matabiau. Practically everything is flavoured with a hint of violet, Toulouse's symbolic flower (cakes from £2.50).

The article 'Southwest France best for boating' was published in partnership with Lonely Planet Magazine.