The Mariuá and Anavilhanas archipelago are both located in the Rio Negro and together consist of more than 1000 islands. They form a unique habitat, which is characterized by the dynamics of the river course.

During half of the year (from March to September) most of the islands are almost completely flooded by the black water of the Rio Negro, so that only the crowns of the jungle giants protrude from the water. The forest floor becomes a riverbed and for the terrestrial animals within the fauna the habitat becomes scarce and they run the risk of becoming victims of predators from the river.
If the water retreats during the dry season from October to February, white sandy beaches appear on the black river, which has formed new sandbanks in its meandering course.

The labyrinth of waterways, islands and flooded forests, on the other hand, has its charm for travellers at any time of the year. While in the dry season there are unexpected bathing opportunities, there are exclusive opportunities in the rainy season to canoe or boat through the Igapó forests.
This special form of the evergreen tropical rain forest characterizes the regularly flooded meadows along the nutrient-poor, humic acid-rich black water rivers of the Amazonia as well as in the delta of the Amazon. In the Igapó the trees are lower than in the not flooded Terra Firme forests.
The non-flooded part of the park is dominated by the vegetation of the Campinarana, which is particularly well adapted to the nutrient-poor, quartz-sand soils and consists of savannah, bushes and forests.

The wildlife of the National Park also includes the emblematic species of the Amazon such as the Amazon river dolphin, manatees, toucans, monkeys, snakes and iguanas. The bird diversity is documented with 232 species.
The Anavilhanas National Park, created in 1981, covers an area of more than 3500 km² and, together with the adjacent Jaú National Park, has been a UNESCO World Heritage Site since 2003.

Note: The nutrient- and oxygen-poor black water of the Rio Negro hinders the development of mosquito larvae, which is why the nuisances hardly occur here.
All accommodations in the area are located on the right bank of the Rio Negro and can be reached by land from Manaus in about 3.5 hours.