We'd been blasting down the Trans Pantanal (Transpantaneira) Highwayin Brazil for hours when, without warning, my driver slammed on the brakes and shouted "Tuiuiu!"

Out in the swamp, 20 yards away, stood the creature whose local name he had exclaimed, a five-foot-tall jabiru stork. The immense, white bird yanked a large fish out of the water, and with beak pointed skyward, began swallowing the thing whole. Before the meal reached its destination, the bird pushed into the air on eight-foot wings and soared -- like a 747 of the jungle -- to a tree-top nest 100 feet above ground.

Where the jabiru' stood, the water seethed with fish. Piranha, jau', pintado, piavucu', pacu and dozens of others with equally exotic names splashed about, while platoons of crocodiles -- their eyes and snouts barely visible above the surface -- cruised languidly in search of prey. Occasionally, one of the beasts would lunge out of the water and drop back in with a belly flop and the loud crunching sound of a hapless fish meeting its maker. Fat and happy, more than 100 caimans -- or jacare', as the Brazilians call these relatives of the crocodile -- lazed on the lagoon's parched banks with their jaws ominously agape.

From a dense clump of sub-tropical foliage came an eerie din. It sounded like a cross between a hurricane, a vacuum cleaner and jet. "Macacos," said my guide. "They're angry because we've invaded their territory." At first, I saw nothing. Then, through binoculars, I saw the howler monkeys' black shadows dancing in the trees. They leaped nervously from limb to limb, cackling at full volume to announce our arrival.

Out on the green flood plain, a ray of sunshine penetrated the overcast sky, silhouetting a small herd of capybara grazing in waist-high grass. It was hard to believe that these broad-shouldered animals that resembled bears are actually the world's largest rodents, close cousins of the guinea pig.

Such was my introduction to the Brazilian Pantanal, among the largest wetlands in South America. Located in the center of the continent, in the Brazilian states of Mato Grosso and Mato Grosso do Sul, this 80,000-square-mile region is alternately a massive flood plain or a lush green savannah -- depending on the season. I spent a quarter of a monthlong journey to Brazil in the Pantanal for the sole purpose of seeing nature in the raw. I wasn't disappointed.

Unlike the rain forests in the state of Amazonas, which hide their treasures behind a thick veil of vegetation and darkness, the Pantanal reveals most everything in broad daylight. What's more, it's astonishingly accessible. Just take a commercial flight from any major city in Brazil to the town of Cuiaba', drive 150 miles to Po rto Jofre down the dusty Trans Pantanal Highway, and you've cut a swath through one of the world's best natural zoos. Here, a pair of binoculars or a zoom lens puts you face to face with some amazing creatures.

Birds are the star attraction. Ibises, herons, storks, egrets, cormorants, parakeets, toucans, macaws, kingfishers, spoonbills, jungle turkeys and hawks are among more than 300 species of birds that run riot in the Pantanal. They horde the available tree space, line the banks of the inland waterways and turn the horizon white when they take to the air en masse.

Mornings, the birds are at their raving best. At sunrise, they'll yank you out of deep sleep with an orchestral mix of whistles, howls, shrieks and yodels that ricochet across the landscape. And, if you're lucky enough to be carrying a high-powered scope, as my guide was, you can get eye-to-eye with many of the area's more reclusive creatures -- like the emu, the bright-orange Brazilian raccoon, or any one of hundreds of small, wildly colored birds that I can't claim to have identified.

What brings these animals here, of course, is food. Each spring, when the winter rains stop, fish that were previously dispersed over thousands of square miles become concentrated in the remaining swamps, lagoons and rivulets. When the evaporation becomes particularly acute, these lagoons are reduced to teaming mudholes that are so jam-packed with fish, many die for lack of oxygen. This makes for an extraordinary concentration of well-fed jacare' and a situation where the normally predatory piranha become prey for birds.

At one such mudhole, I dragged a piranha out of the water with a stick and found that even when it's well fed, the fish's fearsome reputation is justified. Three times in a series of purely involuntary muscle reactions, the piranha snapped off the end of my stick with razor-sharp teeth. In the same fashion, I also examined a fresh-water stingray, a bizarre creature. In the mudddy water it looks like a speckled inner tube with air ducts; out of the water, it looks like an ocean-going ray -- except that it has a long tail, which I later learned can paralyze a person for weeks with its sting. Needless to say, the Pantanal's swamps aren't for swimming.

For those who live here, the Pantanal is cattle country. Ranches, or "fazendas" as the Brazilians call them, generally run from 5,000 to 10,000 acres and support a cadre of landowners whose holdings can be traced to the original Portuguese fortune seekers who came to Cuiaba' in the 18th century looking for gold. Though many struck it rich, thousands more either succumbed to tropical disease or were slaughtered in epic battles with fierce Indians who by the end of the 19th century were either decimated or driven south through the Pantanal into Paraguay. Despite those battles, nearly 100 years later the Pantanal is largely uninhabited.

The reason, according to some conservationists, is that many city-dwelling Brazilians have little or no taste for wilderness. But unlike the Amazon jungle, where man's encroachment has taken serious toll, the Pantanal's raw beauty remains essentially intact -- despite problems caused by initial industrial development, clearing of land for agriculture, use of pesticides and poaching, all of which have caused concern about the environment.

Once you hit the Trans Pantanal Highway, there are no telephones, no electric lines, and only two fazendas directly along the route -- Pixaim and Santa Rosa Pantanal -- where you can spend the night.

Surprisingly, many of the descendants of those Portugese gold seekers who now live here are millionaires, though it's hardly obvious.

At a soda stand on one of the highway's more desolate stretches, I asked a shoeless proprietor who wore stained shorts, a torn shirt and a tattered straw hat how he could make a living in a such a place. He grinned broadly and replied, "If this were all I had, well, there'd be no way." Then, drawing a semicircle in the air with his arm and pointing to the vast green horizon, he continued: "Out there, I own 8,000 acres and 900 head of cattle." He also revealed that he was clearing another 1,000 acres behind the soda stand, that he owned two 18-wheel cattle trucks and a small plane -- the preferred method of travel in these parts, as nearly every fazenda has an airstrip.

In fact, once you make it to Po rto Jofre, where the unfinished Trans Pantanal Highway ends, there are only two ways to go south: by boat or plane. Planes touch down irregularly, and their pilots don't always want company; but boats, carrying livestock, produce and other goods stop at the riverside fazendas almost daily and are willing to take passengers on the three-day journey down the Cuiaba River to Corumba for $15, which includes meals.

However, the best bet, unless you're absolutely determined to see the southern end of the Pantanal, is to dig in for three of four days at the Santa Rosa Pantanal Hotel in Po rto Jofre, where for $20 a night you'll get a sparse but clean room with running water, superb all-you-can eat meals and unbeatable fazenda hospitality. It's the ideal spot to enjoy everything the Pantanal has to offer.

When you arrive, tell the proprietor you want to go fishing. For $10, he'll send you out for half a day on the Cuiaba' River in an outboard-powered skiff to help one of the fazenda's fishermen haul in the day's catch. They'll take you to their favorite spots and show you their fiendishly simple technique.

Take a roll of 60-pound test line, tie on a steel leader, add weights and thread a foot-long worm on a large hook. Pay out 20 yards, grab a couple feet and swing the setup around your head like a hammerthrow. When the momentum's right, let the payload fly and drift downstream. The fish don't take long to respond.

The piranha, true to reputation, attacks the bait viciously, but doesn't weigh enough to put up much of a fight. Locals regard it as a junk fish because it's too bony to eat; but they still use it to make a pungent, viscous soup, which they claim is an aphrodisiac. I couldn't stomach enough of the stuff to test their claims. The jau, on the other hand, weighs four to 50 pounds, and at the heavier weights will give the unsuspecting novice a monstrous adrenalin rush when it leaps for freedom. The pintado, which looks like a dark, spotted catfish, isn't nearly as large or as exciting to haul in as the jau, or Brazil's most famous game fish, the dorado, but it does have an exquisite flavor.

Flavorful fish -- that's reason enough to come to the Pantanal.

While the heavily spiced fare of Bahia is said to be the jewel of Brazilian cuisine, I found the simpler preparations of the Pantanal to be superior. No place, except in comparable jungle waterways, will you find fish that are so rich, so succulent and so explosively tasty. Whether broiled over wood, pan-fried in dende oil and onions, or rolled in a meal-like flour called manioc and deep-fried, fish are soul food of the highest order. Eaten with a sumptuous heap of rice and beans, washed down with endless rounds of cold beer and complemented with fresh tomatoes, marinated carrots and a dessert of fresh pineapple, papaya, banana and cake -- Pantanal fish are guaranteed to make you as fat and happy as the jacare' that cruise the area's rivers and swamps.

During the humid heat of the day, you'll walk it all off, tracking birds andanimals and following your instincts.

My first night at the fazenda, I fell asleep to the sound of cattle chomping grass outside my window, and awoke in the morning to jabbering parakeets. With camera in tow, I walked outside and wound up spending an entire day tracking spiny-legged jabiru, navy blue hyacinth macaws, pairs of low-honking toucans and the capybara, which keep their distance by taking headlong dives into piranha-infested waters.

I never got close to the howler monkeys. Each time I'd walk the requisite three or four miles to their hideout, they'd have moved on, leaving me to slosh about in the tall, mushy grass and be victimized by the kind of vile thoughts that can haunt you when you're alone, unarmed and things are too quiet. I thought about jaguars lurking behind the trees, anacondas that become crazed with hunger during the dry season and poisonous vipers slithering through the grass.

Then, I recalled the pact I'd made with myself to stay at the top of the food chain on this trip, and beat a retreat.

At the fazenda's communal table, I ate, drank and joked with the tour guides from Cuiaba'. I played ping pong with the farm hands; sang sambas with a group of Argentines. And when the rhythms got particularly felicitous, I joined the guests who beat out accompaniment on glasses, bottles and cans in a spontaneous percussion ensemble worthy of "Black Orpheus."

But be warned that the Pantanal is not a luxury vacation. Accommodations are sparse, and air conditioners (given the dearth of electrical power) are few and far between. But with the sheer quantity of raw nature one can see in this place without getting scuffed up, it's difficult to imagine longing for the comforts of home. Fact is, there aren't too many five-star hotels where you can hobnob with jabiru, jacare' and capybara, catch mouth-watering tropical gamefish and relax completely.

That special kind of "luxury" is what makes the Pantanal such a feast for the senses.