The world's mightiest river, the Amazon flows for a whopping 4,000 miles with a volume some 11 times that of the Mississippi River. While that's impressive, more so is the land surrounding the river, which serves as the ecological cornerstone for forests of dense flora and fauna that cover half of the country while housing a mere 7 percent of Brazil's population.

The Amazon EcoPark Lodge (011.55.21.2547.7742; www.amazonecopark.com.br), located deep in the Amazon Basin about a 30-minute boat ride from Manaus on the Rio Tarumã, which flows into the Rio Negro (which flows into the Amazon), comes with thumbs-up reviews from travelers posting tips on several online forums. Little wonder. This property is surrounded by rainforests, savannas, and, of course, waterways that scientists are still working to understand and document. About six miles of trails extend from the property to give guests room to roam through forests of giant trees and orchids. The complex consists of 20 bungalows, each with three rooms, and all are made of wood, with air conditioning, screen windows, and individual porches and bathrooms.

But it's the 4,500 acres preserved around the lodge that makes this place worth all the DEET you can bring. Next to the lodge you'll find a project created by the Living Rainforest Foundation called the Monkey Jungle. As you may have guessed, the jungle here includes protected habitat for spider, wooly, squirrel, and capuchin monkeys that have been rescued from the rampant burning of Amazonian forestlands by timber loggers. Come down between 11 a.m. and 4 p.m. to watch workers feed their simian friends.

Should you ever wish to strike out into the Amazon on your own, be sure to sign up for the lodge's Jungle Survival course, taught by officers in the Amazon Jungle Brigade. These gurus on all things moist and mucky organize several workshops where you can learn how to build a shelter from vines and palm fronds, make a rope bridge, trap critters, and extract latex from rubber trees (in case you want to make a rubber hat or a tire). You'll also learn what plants you can eat, and which will make you sick.

During some of the outings on the rivers themselves, be sure to look for pink dolphins while fishing for piranhas. Or head out on the river at night in a canoe to look for alligator eyes reflecting red in the beam of your flashlight. And before you go, catch the sunrise from a canoe while listening to the cacophony of birds.

Packages including accommodation, meals, and most activities start at $265 for two days and one night. Best to stay for at least four days and three nights for $440. Go in the fall, before the rainy season really kicks in during November through May.