The Tambopata River system is an amazing, undeveloped wilderness. Protecting over 1000 square miles of pristine rain forest, Tambopata is one of the most biodiverse areas in the world.
Where: Puerto Maldonado in Peru is the gateway city to Tambopata National Reserve, which protects the Tambopata wilderness.
When: Tambopata is drier from April to November. The rainiest months are January and February (even during the rainy season, you're not likely to get rained on too much). The rainy season is when macaws are nesting and more active on the clay licks. December through February, when nesting season is in full fledge, is the best time to see macaws.
Photography: A journey into the heart of the Tambopata is an immersive experience. There are a number of ecolodges in the rain forest interior, which can serve as bases for photography and exploration. Accommodations are often rustic and reachable only by boat, so pack light! Photography in the rain forest can be challenging. Conditions are typically dark, requiring high ISOs to compensate; a tripod can be useful to help stabilize heavy lenses in low light. Long telephoto lenses are necessary to capture photos of Tambopata's wildlife. Expect to do some walking to find wildlife, although you can also have excellent sightings from the lodges. Make sure to plan a visit to one of Tambopata's clay licks to photograph parrots and macaws.
Learn more: Rainforest Expeditions offers a really good summary of the Tambopata experience, and they can also arrange tours to visit their ecolodges.