The Amazon rainforest may get all the media attention, but it is Brazil’s Pantanal region (which spills over into neighboring Bolivia and Paraguay) that has all the wildlife. This unique ecosystem of lakes, rivers, grasslands, and forests is overwhelmingly vast (the size of Great Britain) and amazingly unspoiled.

The largest wetlands on the planet, the Pantanal (pantano is Portuguese for swamp) is actually not a marsh, but a floodplain that lives in function of the ebb and flow of the giant Rio Paraguai and its tributaries. The fact that most of its area is underwater for six months of the year means there is little human encroachment aside from traditional cattle fazendas (farms).

As a result, native fauna have the run of the 130,000-square-kilometer (50,000-square-mile) territory. Jacarés (caimans), for instance, far outnumber both human beings and cattle, but there are also 30 frog, 500 butterfly, 400 fish, 650 bird, and 75 mammal species—all in fantastic abundance and largely unfazed by human presence.

The creatures you’ll come across often seem to have emerged from a mythological menagerie. Aside from giant anteaters, giant armadillos, and giant river otters, you’ll also encounter the world’s largest rodent (the Alice in Wonderland–worthy capybara, which can weigh up to 45 kilograms/100 pounds); largest stork (the red-necked jaribu); largest flightless bird (the greater rhea, an American cousin of the ostrich whose eggs alone are things of wonder); and the largest snake (the infamous anaconda—which, although it grows to lengths of 9 meters/30 feet, defies its Hollywood reputation by being somewhat of a shy loner).

Rarely seen but avidly sought after are the spotted jaguar and jewel-like hyacinth macaw, which can measure up to a 1 meter (3 feet) from tail to beak. The bird’s size and stunning cobalt blue and banana yellow plumage have earned it the going rate of tens of thousands of dollars on the black market as well as endangered status.

Spanning the states of Mato Grosso and Mato Grosso do Sul, the Pantanal is a difficult region to travel through. Distances are enormous and roads are scarce. Although the highways linking the major towns are in reasonable shape and have ample bus service, the dirt tracks that approach (but don’t enter) the Pantanal itself are often only navigable by four-wheel-drive vehicles—in the dry season. “Doing” the Pantanal on your own is only for the very brave and Tarzanic. The best option is to organize an eco-safari—either individually (more expensive) or as a group (cheaper) out of one of the major access towns: Cuiabá and Cáceres (Mato Grosso) or Campo Grande and Corumbá (Mato Grosso do Sul).

Although you can explore some regions by Jeep, truck, and horseback, to go deep into the Pantanal requires taking to the rivers in small boats or canoes, which can be hired in outposts such as Porto Jofre. Most tours include accommodations at fazenda lodges. These working cattle farms, located deep within the Pantanal, offer accommodations ranging from simple to luxurious along with guided tours and activities such as boating, horseback riding, and fishing. Another option is to book yourself into a fazenda lodge in advance (often a cheaper alternative) and then let the hotel take care of all your needs. Those with extra time and money can indulge in the eco-tours offered by “luxury” houseboats, which is the best way to see more elusive larger mammals such as jaguars.

Since the Pantanal can be both wet and downright inundated, when you show up makes a significant difference. During the rainy season (November–March), river levels can rise by up to 3 meters (10 feet), transforming the area into a vast lagoon interspersed with islands of green vegetation where the local fauna takes shelter. Throughout this period, boats are the only means of access. In contrast, during the dry season (April–October), the water recedes, revealing grasslands and dry forests in coppery earth tones. Although the vegetation is less exuberant, it is easier to spot wildlife as the fish trapped in disappearing pools provide banquets for birds and animals who gather in vast numbers.

No matter which season you choose to visit, mosquitos are rampant, so bring plenty of repellent as well as long-sleeved shirts and pants made of lightweight material. You’ll need them, even though the daily temperature is hot year-round (nights can be cooler). Although malaria isn’t a problem, you do need to get a yellow fever shot. Since the Pantanal is a remote region, make sure you come equipped with sunscreen, any medication you might need, and a good pair of binoculars.

Fishing enthusiasts be warned that the Pantanal is one of the best places in the world to go fishing (the season lasts from March to October). To this day new species are being discovered. In terms of traditional favorites, trying sinking your hooks (and teeth) into the highly prized piraputunga and dourado, as well as pacu, pintado, and surubim. The most classic catch, of course, is the infamous (and surprisingly delicious) piranha, which can be easily lured by baiting a hook with a chunk of raw steak.

Culturally, the Pantanal is an interesting place, as are the states of Mato Grosso and Mato Grosso do Sul, which retain a rugged Wild West flavor. Although many of the Indian groups that originally occupied the area were largely wiped out by colonists, descendants survive on reservations and their cultural and culinary influence is quite pronounced. Other notable influences include those of the intrepid Paulistano bandeirantes who first explored the area, the ranch owners of Spanish and Portuguese descent, and the Gaúchos who emigrated from the South to take care of their herds. Although these days cattle ranching is increasingly mechanized, the cowboy is still a strong presence despite the fact that an increasing number of fazenda owners are finding ecotourism to be more profitable (and sustainable) than ranching.