Strangely, Brazil offers no equivalents to the riverboats on the Peruvian Amazon operated by Aqua Expeditions, which offer sophisticated levels of comfort and cuisine. But, of course, most of the Amazon ecosystem is in Brazil. If you wish to venture into this extraordinary environment, I recommend signing up for a cruise with the specialist Brazilian company Matueté. It can offer a variety of vessels, including private yachts for as few as eight people, staffed by talented chefs and knowledgeable naturalist guides. Amazonia is full of surprises: For example, the Rio Tapajós tributary has translucent water and white-sand beaches off of which it is possible to swim. The region’s large animals — jaguars, tapirs, sloths — are often hidden by the dense forest, but resplendent birds, huge butterflies and river creatures such as caimans (native alligators) and pink dolphins are commonly encountered. Such trips will appeal to more adventurous travelers who are genuinely fascinated by wildlife and ecology. The best (driest) months for travel in the Amazon are August through October.