While we watch, a bird appears. And a great sun. The artist in white overalls on the high scaffolding scratches freehand and fast in the wet plaster. Stick in hand, he waves down to us, clowns for our 2-year-old grandson, then adds a flourish to a wing. Our cameras click to record this newest bit of sgraffito in the making.

Sgraffito is a form of rough decoration produced by scratching into a fresh plaster coating smoothed over house walls. The scratched lines take on, from sun and air, a color different from that of the surface and the plaster undercoat.

It's a tradition in the Swiss Engadine, which is part of the canton of Grisons in the country's far southeastern corner between Austria and Italy. Sgraffito can be found in Switzerland only in the Grisons, where it adorns villages of massive farm homes that exist nowhere else in the world.

Against fierce mountain cold these homes have sheltered families, hay, animals and the precious manure heap for centuries -- all under one broad roof. They were built on a bold scale, three or four stories high, with great timbers, stone walls a meter thick, small window openings scattered in a random pattern and huge arched doorways. Yet with their scratched-on "stonework" around the windows and around the haywagon-accommodating doors, and with their fancifully scratched sirens, swirling discs and winged pigs, birds and dragons, they mimicked airy palaces to the south in Italy.

Today, in a rush of renovation and new building, sgraffito is much in evidence. And sgraffito-watching adds to the pleasures of walks. Such pleasures are many, my husband and I discovered during a two-week ramble in Switzerland with our two children and five other family members.

The Engadine, the high valley of the River Inn, is made for walkers and watchers like us who like to be out all day on foot without having to face fancy footwork and extensive climbing. In length it is a mere 60 miles, measured in a straight line. Yet this grassland, rimmed by snowy peaks and dotted with towns, is so overlaid with a network of trails that it's possible to head out from one base location on a summers-long series of day trips without ever retracing footsteps.

We headquartered in Zuoz because it's the liveliest and handsomest of the towns in the valley, because it's unsurpassed for sgraffito both old and new, and because it's where I've happily gone many times since my first visit in 1925 -- at age 2 -- to my grandmother Gilli.

This time we rented a modern vacation home that cost about $40 a day. We quickly developed a daily pattern, heading out each morning on the 8:30 train to towns along the line. On foot we'd follow one rushing stream or another up through a side valley till it opened out into a great grassy bowl and to vistas and more trails beyond. Or, after cadging rides from funicular, chair lift or cable car, we'd walk the high contour trails with their views out toward peaks and down past woods to azure-blue lakes and the frothing Inn.

On the lower reaches we'd watch men and women haying with scythe and rake, and we'd stand aside in cobbled streets as tractors and loaded wagons rumbled past -- some to be squeezed through arched doorways, some to have their hay blown directly to lofts.

All through the towns we peered into gardens with their cheerful mix of poppies and cabbages, lupine, cauliflower and summer-blooming lilacs. We marveled at the blocky shapes and angles of houses and collected on film their ironwork and their scratched-on decoration. And all along the way we sampled teas and tart plum tarts, barley soups and saffron-flavored risottos as well as paper-thin slices of air-dried beef, all local specialties.

If you are a first-time visitor, join one of the historical tours of Zuoz, which begin Wednesday afternoons at 4:00 from the fountain in the main square. It will give you a grip on the history of the area, including the defeat of the Celtic Rhaetians in 15 B.C. by the Romans, who thought this eyrie too cold but who coveted the control of mountain passes it provided; the crystallizing of the Romansch language you hear today ("We who live here," said our guide, "distinguish four Romansch dialects, and we can pinpoint a speaker's town of origin"); the rule of Charlemagne, from 780 A.D., whose church in Mu stair merits a visit; the ownership of the Engadine by the Bishop of Chur in the 11th century; the fire of 1499 in which Zuozers scorched their town to the ground and repelled the armies of Hapsburg Emperor Maximilian; and the Reformation preached in the 1550s by humanist Gian Travers, who was the first to write in Romansch.

This tour will lead you through the cross-shaped village where, Roman-style, it's the neighborhoods, not streets, that have names -- such as San Bastiaun, for the church of St. Sebastian built beside the Rhaetian sacrificial stone, or the Chaunt da Luf, a place of wolves. You'll see where stone watchtowers have been incorporated into houses, how kitchens are vaulted and living rooms are lined with wood and have tiny stairs leading through a trapdoor to the bedroom above.

Zuoz's only sgraffito artist, Constant Ko nz, almost surely will be out on some high scaffolding, but you'll see his house. Ko nz, with his brother, is largely responsible for the present-day flourishing of sgraffito art. You can scarcely miss his house, which is the color of cornmeal, or his studio tucked behind, where an undistinguished doorway is ornamented by sgraffito dog, cat, birds and exuberant bouquets.

Should you watch this loose-limbed, lanky draftsman at his work, he will tell you how villages have distinctive colors based on their local sands. He'll answer anything you wish to know about preparing a surface or mixing the plaster, but be warned: His recipes give proportions of sand to lime by the wheelbarrow-load.

Exploring other villages, you can apply what you've seen in Zuoz. A rule of thumb is that around Zuoz, in the Upper Engadine, early motifs tended to be geometric; in the Lower Engadine, in Ardez for example, motifs were more fanciful-fantastic.

At least one Zuoz resident we talked with, an architect, has some misgivings about sgraffito's resurgence. "When our buildings had crooked edges, lines that were off-sharp, imperfect angles, this rough kind of decoration was important. For the eye it created intervals across vast surfaces. It gave order and a rhythm and some grouping to the randomly spaced windows. In new construction, where lines are straight and window framing is razor-sharp, the decoration can look mechanical." It becomes, he thinks, a kind of doodling or permanent graffiti. Certainly there's a danger of an overload of decoration (we began to feel it in the village of Chamues-ch) -- or worse, a Disneyesque effect.

Some suggested day trips:

*From Punt Muraigl: A half-day walk on a contour trail along the Muottas Muraigl, which is wide enough for a baby stroller (though you may need to clear the way by rapping cows on the flank), is as easy as it is spectacular. Changing views include the chain of lakes (Silvaplaner, Sils, St. Moritz) stitched together by the Inn and, farther along, the Morteratsch glacier and snow-capped Bernina Alps. Take the funicular up and chair lift down for tea on a sunny terrace in Pontresina. Save time for look-ins at such towns as Bever or Madulain, for there's little architecture in Pontresina to brag about, or in neighboring St. Moritz either -- though that posh town's traffic jams are to be braved in order to see the museum of Post-Impressionist Segantini's paintings.

*From S-chanf: Guided tours in the National Park -- the country's only park set up expressly for the protection of plants and wildlife -- some serving a sunrise polenta breakfast, give the best chance to see game, though ramblers heading on their own into the Val Trupchun also will see marmots popping in and out of holes, and possibly deer, elk or steinbok.

*From Samedan: Go by one of the topless railway carriages, then continue up by cable car to the Diavolezza, and note the ease with which the soft-shoe walker is lifted to this shelf, face to face with a crescent of snowy summits. Rocky outcrops in fields of snow make good picnic spots. If you opt for the steep walk down, allow three hours with stops by emerald ponds. Or, for a more ambitious descent, join a daily guided "glacier wandering."

*From Sils Maria: Val Fex, neighbor to bleak Fedoz, is the bonniest of the valleys, where pensions serve outdoors on dappled tablecloths. Berries abound, along with the prettiest flowers in Switzerland. Here transport is by horsedrawn bus or on foot. A walk to the glacier and return trip, with a choice of sunny or shady paths, makes for a good day. Signs point to hikes beyond, one to Lej Sgrischus, a lake that has trout (though it's locked in ice for nine months) and edelweiss blooming on its shores.

*From Albula Pass, above La Punt: Walk two hours to Chamanna d'Escha, the hut used as the starting point for ascents of Piz Kesch. This path, entirely above treeline, is never steep and has long switchbacks and see-forever views.

*From Brail: Thread your way up the uninhabited Val Susauna, where Alpine roses appear in clumps among the field flowers and further on fill whole hillsides.

*From Maloja: On a clear day treat yourself to a geography lesson with a hike up Piz Lunghin -- not to the peak itself but to a lesser ridge where melting snow drips into waters heading for the North Sea, the Black Sea and the Adriatic. It takes six easy hours round trip. Here the infant Inn (so narrow you can jump over it) babbles through buttercups and Queen Anne's lace and the small purple tufts of ma nnertreu. You pass a lake and cross snow to reach, above, patches of grass.

In the Engadine the play of light has a great deal to do with the pleasures of the walks. Here grass and sky are luminous and air shimmers. You wake (that is, a riotous ringing of church bells wakens you at 5 a.m.) to whiteness. But when mists shred, the sunlight is strong and intense, bone-penetrating. It glances off the plaster house facades, casting the set-back windows into deep shadow. Summer dusks are long. Cows crossing an Inn bridge are haloed. Peaks go black, against inky skies.

One doesn't cross the Atlantic for a light show, yet we've found it's the light that's remembered.Peggy Thomson is a free-lance writer.