Flowing through the heart of the Brazilian Amazon, the Rio Negro is one of the world's largest blackwater rivers and the Amazon River's most significant tributary. Renowned for its dark, tea-coloured waters, which result from decomposing vegetation and low sediment levels, the river winds through vast stretches of pristine rainforest teeming with wildlife. Visitors can explore its intricate network of waterways by boat, spotting pink river dolphins, giant otters, caimans, monkeys, and an extraordinary variety of birdlife. One of the region's most famous attractions is the Meeting of the Waters near Manaus, where the dark waters of the Rio Negro flow alongside the sandy-coloured Solimões River without immediately mixing. The river also provides access to remote Indigenous communities and some of the most biodiverse ecosystems on Earth.