Just outside the train station in the Swiss town of Sion, a yellow signpost points hikers in two main directions with no fewer than 16 routes to choose from. As you cross the medieval downtown, keeping the Valère Basilica and the Tourbillon Castle on the right, aim for the Valaisanne Brewery. If you can resist the brewery’s new tap room and its outdoor tables, be sure to duck as you scramble up a staircase and through the tunnel of holly and its busy bees and onto the Bisse de Clavau and 500 years of history.

Now you can relax. The babbling flow of water soothes the soul and the Valais sun warms the body. The Bisse de Clavau was built in 1453 to irrigate the terraced vineyards in the region, which is the driest and hottest in all of Switzerland. A bisse (rhymes with peace ) is a narrow (two- to six-foot wide) canal that brings water from high-altitude rivers across mountains to irrigate pastures and vineyards.

From the 11th to the early 20th century, about 300 bisses (stretching about 1,200 miles in all) were dug by hand, primarily in the Valais Canton, which is bisected by the Rhone River Valley. Centuries ago workers dug up the channels, flinging the mud and debris next to the canals, thus forming a berm that was used as an elevated walkway. To this day, 80 percent of all pastures and vineyards in Valais are irrigated with water from the bisses, while the paths that run alongside them are excellent for walking or trail running.