Buildings, history, beautiful bodies -- none of that interests the nature lover. What they want to see are trees, birds, butterflies, and animals lurking and playing in their native habitats.

Days 1 & 2: Rio de Janeiro

Yes, it's a city of 12 million. But it's one of those rare cities with an intimate relationship with nature. Instead of the busy beach neighborhoods, stay in one of Rio de Janeiro's small B&Bs in hilltop Santa Teresa. Take a guided hike through the Tijuca rainforest with Rio Hiking. Take a walk below the Sugarloaf by Praia Vermelha, and admire the bird life and rainforest and with luck, the troupe of marmosets that make their home on the hillside. Go up to the Corcovado, look down at Rio, and see how ocean, beach, city, and forest merge into one.

Days 3-6: The Pantanal

Then catch a flight to Cuiabá and head down the Transpantaneira into the Pantanal. This flooded landscape is a bird-watcher's dream, so bring your binoculars and several pencils to keep track of all the new species you'll be seeing.

Days 7-12: The Amazon

From the Pantanal, fly north to the Amazon. The species diversity is greater here, but the very richness of the foliage makes the animals and birds much harder to see. So enjoy the trees. And the monkeys, and dolphins, and parrots. Go out on a kayak trip on the upper Amazon with Amazon Mystery Tours. Or head for one of the lodges far from Manaus, preferably the Mamiraua Reserve.

Days 13-16: Fernando de Noronha

From Manaus, catch a flight all the way out to Fernando de Noronha. A vastly different ecosystem, this semidesert tropical island is home to large schools of spinner dolphins, not to mention the sea turtles that lay their eggs on the island's long beaches. If you scuba dive, bring your gear. If you don't, there's still plenty to see above the surface of the water.

Days 17 & 18: Iguaçu Falls

Take the long flight all the way south to Iguaçu Falls, one of the natural wonders of the world. Astonishing enough in themselves, the falls create a misty microclimate perfect for toucans, dusky swifts (which actually nest on the cliff behinds the waterfalls), and bright, colorful butterflies. In the rainy season, thousands of the colorful insects float and flutter at the edge of the roaring falls.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.