THE RIVER IS the constant in the Val Verzasca, one of Switzerland's lushest, least-known and most beautiful valleys. From the green, churning Verzasca River, the valley gets its character and its name. Like an arrow ever descending, it cleaves the valley in two. Only minutes away in travel time from Locarno in southern Switzerland, yet light years away in mountain setting and mood, the valley engulfs you with its cool, lung-bracing air, its tranquility and, above all, the sound of the rushing water.

These joys of nature were ours during two summer weeks my wife and I and our three daughters spent exploring this lovely valley. With the assistance of the Ticino Tourist Office in Bellinzona, we found a chalet apartment with a gorgeous view in Gerra, a village high in the sparsely populated valley. Our family delighted in the river and its boulders, the villages and their unique stone houses and the cinematic view offered by a bus ride. We gathered most of our impressions, however, on walks, including one exhilarating dawn-to-dusk hike.

The valley's excellent 29-kilometer mountain road, climbing from a low point of 300 feet above sea-level to 3,000 feet in Sonogno at the end of the valley, takes about an hour by car, but driving up the valley can be nerve-racking. So riding the big yellow PTT bus from the Locarno train station is preferable. The Locarno-Sonogno run is scheduled to take just over an hour. However, even though the buses and their unflappable drivers always have the right of way, they are at the mercy of traffic, road work and cows crossing in front of them. Once--much to the delight of passengers, driver and the local villagers--a small helicopter landed on the road on its way to make a delivery to shepherds in the Alps.

A panorama unfolds above and below: the villages, the huge blue lake (behind a dam), the hanging bridges, the many waterfalls, the jagged mountains on both sides, the frothing river and its enormous boulders. And by riding the bus, you also get to meet the friendly villagers and hear their unique Verzasca Italian dialect, which has a curious, musical Swiss-German lilt.

The Verzasca starts as a pleasant, bubbling mountain stream outside of Sonogno. In the clear, cool evenings, the flow of the water usually is the only sound in the valley. Because of the difficult drive, no buses run after sunset. But the silence is occasionally broken by a new plague: motorbikes.

One gets to know the massive, overpowering boulders in the river and can understand why the houses are made of stone and why the Verzascans became famous as stone masons. The huge rocks seem to glow with a matte-white light at dusk, offering a contrast to the green hills. Some look like petrified redwood logs; others are rippled as if a wizard had changed a swift current to stone. The ones that are long and alligator-shaped are best for sunbathing--but swimming is strictly forbidden in the treacherous Verzasca current.

The villages are picturesque in their diversity. Gerra, the third village from the valley end, is perched on the side of the mountain. Frasco (the next to last village) is built in layers from the riverbed up to the mountain road and beyond. Alnasco is the only village that lies flat on river-level terrain. Corippo seems to nestle like a castle sculpted out of the crags.

One characteristic, however, binds them all: their architecture. The old houses (angled roof, walls and foundation) are built solely of gray granite slabs. They huddle together as if for security and warmth, yet none looks out at another, so privacy is assured. A colorful umbrella on a patio hints that modernity has invaded at least one of these centuries' old houses. Thick white frames are painted outside each window--a valley tradition to ward off demons.

During our long hike through the valley on a ringingly clear, cool blue-sky day, we passed two carless villages. To reach Alnasco, one must go down from the road and cross the river via a long, narrow, hanging footbridge. Cars are left above, and a pulley system sends packages from the parking area. The natives are gone (emigration has been sizable throughout the valley), and the village is now settled only in the summer by 60 vacationing families from the Ticino.

On the way to Corippo, we began to hitchhike (not easy with five people). A kindly driver named Urs stopped and took us up the long winding road. He left the car at the village gate, where we had an imposing view of the whole valley, and we helped him carry five heavy bags of groceries through the narrow cobblestone lanes to a meadow behind the last stone house.

Urs placed the bundles into a large metal basket attached to a long, thick cable that led up to a distant mountaintop. He rapped the cable three times with a stick. As if by magic the cable soon hummed and twitched three times. The basket began its slow ascent. "Sometimes," he said, "I ride up there with the food."

Urs, a widower in his late forties, asked us to join him on the climb to a tiny, isolated farming settlement where he was going to visit a young widow. For 45 strenuous minutes we hiked up to Heidi-land on a well-trod, century-old path. We hopped across streams, walked over wooden planks and climbed up huge, hand-laid stones placed as steps, went single file across makeshift wooden bridges and edged our way carefully on the narrow trail on the side of the mountain. It was scary, exciting, but not unsafe.

At the top we saw an incredible sight. One hundred feet below us a man and two women were scything hay on a broad 50-degree slope that seemed to end in an abyss. It made us dizzy just watching them. We pressed closer to the uphill embankment. They waved and clambered up as deftly as mountain goats to greet us. The man proudly displayed his newly pine-paneled stone house. Then the widow took us to her cottage, whose stone walls were about 10 inches thick. Because of the late afternoon chill, a fire was going in the small fireplace and three young children were sitting in front of it. The house had electricity, but a mountain spring provided water. Before the electric pulley, the residents would come down twice a month for provisions, carrying everything back up on their backs.

Shopping in Gerra is no problem, despite the lack of stores. Twice a week the noted Swiss supermarket chain, Migros, sends a well-stocked truck up the valley. Bread is usually available daily. Once, on a walk down the valley, I saw leather bags tied to the fencing. They were empty (save for the coins within) awaiting the bread man.

To our knowledge, we were the only Americans in the valley. We were also the only tourists without a car. Since car rental is exorbitant, we used the PTT buses gladly, having purchased the Swiss Holiday Pass, the best travel bargain in Europe, which gave us unlimited use of postal buses (they go to the most breath-taking places), trains and lake steamers.

For vacationers who grow weary of preparing their own meals, there are restaurants in Sonogno, Lavertezzo and Brione; in Frasco there is a charming hotel and restaurant. Spotless rooms and apartments can be rented almost anywhere in the valley. Remember, however, in the Val Verzasca there are no resort towns. The Val is for the person who prefers nature's gifts. (To secure accommodations, it is best to write in advance to the Swiss National Tourist Office in New York or the Ticino Tourist Office in Bellinzona for a list of hotels and apartment chalets.)

Not everyone comes to the Val Verzasca to walk, but you cannot experience a village by driving through its main street. By walking you learn the interior contours of a place, its human dimensions. Once, before I was aware of the odd post office hours (8:30-9:15 a.m. and 3-4:45 p.m.), I walked to Frasco to place a call to Zurich. I came at 9:20. A woman in a house next door noted my frustration and invited me to use her phone. She not only refused payment but also gave me a tour of her 350-year-old stone house. I wouldn't have minded the lovely 10-minute return hike later that afternoon, because I remembered what Urs had told me during our long hike (thinking no doubt of his young widow):

"The difference between riding and walking in the valley is the difference between watching a beautiful girl being kissed and doing it yourself."

Curt Leviant's novels include "The Yemenite Girl" and "Passion in the Desert."