Alter do Chão region features unique meeting of Tapajós and Amazon rivers

The meeting of the Tapajós and Amazon rivers near Santarém, in the state of Pará, creates a distinct natural phenomenon where the two bodies of water run side by side for approximately eight kilometers without immediately mixing. This visual separation is caused by differences in sediment levels, density, temperature, and velocity; the Tapajós is relatively clear, while the Amazon carries heavy sediment from the Andes.

The landscape of the region, particularly around Alter do Chão, changes significantly with the river volumes. Between August and December, low water levels reveal white sand beaches, whereas from January to July, high water levels allow for navigation through flooded forests. Alter do Chão has been recognized as a significant destination, previously named the most beautiful freshwater beach in the world by The Guardian.