One bright October afternoon two days before harvest, Swiss winemaker Blaise Duboux chucked a fallen quince over the iron fence girding his terrace and into the sloping vineyard next door. It should have easily rolled 600 precipitous feet down to shimmering Lake Geneva, plied by stately steamers and backdropped by the snowcapped French Alps across the water. But some 40 levels of terraces staircase the hillside, intervening.

"The monks stopped gravity," explained the 17th-generation winemaker. "In the Lavaux, everything is handmade."

He refers, of course, to the local wines, but also to the Lavaux itself, a 2,000-acre patchwork sown across 10,000 small parcels upheld by miles of stacked stone walls, on the Swiss Riviera between Lausanne and Montreux.

In Switzerland's food hall of fame, chocolate and cheese easily overshadow wine. But only from a foreigner's perspective. Here, wine is a matter of civic, if not national, pride; the city of Lausanne, for example, owns five wineries. Cultivated for centuries, Swiss wine is so popular in Switzerland that most of it is drunk domestically.

Switzerland, too, claims its own unique grapes, the red gamay-descendant Plant Robert and the light, bright white called chasselas. The latter accounts for 80 percent of grapes planted in the Lavaux, deemed a UNESCO World Heritage Site not just for its beauty but, given the 45-percent grade of its best appellation, its improbability.

Beginning in the 11th century, Cistercian monks, courted by the bishops of Lausanne with the lakeside land gift, began clearing the south-facing, pine-covered slopes to plant vineyards for the church. Later, the friars trained area farmers to maintain the labor-intensive plots with the hope that their knowledge would be passed down through the generations. In both landscaping and recruitment, they were successful, as family winemakers a millennium hence have continued to tend the needy terraces, patch the walls and cultivate the vines.

The Cistercians grew red grapes, but winemakers long ago switched largely to white to better showcase the soil varieties forged by Alpine geology and glacial carving.

"Chasselas is a soil revelator, and the terroir here varies greatly," said Duboux, in a rare break from pre-harvest preparations at his winery in the tiny town of Epesses. "The Rhine glacier made a real patchwork here. It gave us 100,000 years of up and down and freezing. I'm trying to be as close to the character of the soil as I can, going parcel by parcel to reveal each one."

Seven appellations make up the Lavaux, with two boasting the highly rated Grand Cru distinction: the steepest section known as Dezaley, and its neighbor, the rocky Calamin. An impressionable grape, chasselas varies from richly honeyed Dezaley to more mineral Calamin, with subtle variations across the unoaked spectrum (most chasselas is aged in stainless-steel vats).

"For me, chasselas is the grape that goes with all food," said Jerome Ake Beda, sommelier of the celebrated restaurant Auberge de l'Onde in the medieval village of St. Saphorin, another of the Lavaux appellations. "It's the king of the cepages (grape varieties). You finish eating, and you feel light."

I polished off my lunch of lake perch at Auberge de l'Onde — a favorite of late local resident Charlie Chaplin — with a glass of chasselas midway through a daylong hike among the vineyards. Most of the roads that switchback throughout the terraces and link the ancient villages are closed to all but winery vehicles, inviting traffic-free walks between tasting cellars. An eight-minute train ride from the lakeside city of Vevey to the hilltop village of Chexbres puts most of the routes, which have good signage, downhill.

Plaques along the way highlight the mix of geographic and human-made gifts that bless the Lavaux. Vines here are warmed by the trois soleils, or three suns: the one overhead, another reflected off the lake — the largest in Switzerland — and the radiant third, stored by the ancient walls. The mild climate suits chasselas, pressed into a friendly quaff in which alcohol levels generally run 11 to 13 percent.

"Our wines, first they are all light," said Patrick Fonjallaz, another Epesses winemaker who counts 13 generations in the business. "We want them light. I want to have wine where you can drink three glasses and not grip the table."

To prevent future development from crowding out winemakers, locals united to seek UNESCO World Heritage Site status. Awarded in 2007, it ensures that the vineyards will remain productive rather than excavated for homes of the rich and famous who reside in cities like Montreux, just 20 minutes away by train.

"We must preserve this region not as a museum, but as a living thing that produces," another winemaker, Louis Bovard told me, standing on the shore of Lake Geneva in the town of Cully and gesturing to the surrounding hillsides, where a helicopter — the most efficient transport in the region — had just plucked a crate of harvested grapes to ferry to the presses.

If you go

Tours: Sunday morning and afternoon tours of the Lavaux wine region through Oct. 30; www.lavaux-unesco.ch/en/N9214/regular-guided-tours.html. For those who prefer not to walk, the Lavaux Express trolley runs on various routes through Oct. 30; www.lavauxexpress.ch/en.

Lodging: A few of the wine towns offer atmospheric lodging, including Cully, home to the inn Auberge du Raisin (from roughly $133) with a destination restaurant; www.aubergeduraisin.ch. The lakeside town of Vevey, home to the elegant Grand Hotel du Lac (from $275), makes a great base for day trips in the wine region; www.hoteldulac-vevey.ch.

Dining: Reserve a table at Auberge de l'Onde in St. Saphorin; www.aubergedelonde.ch. Near Chexbres, the outdoor terrace Le Deck at Le Baron Tavernier hotel overlooks the vineyards and the lake; www.barontavernier.ch.