Marajó

Marajó is an island in Brazil at the mouth of the Amazon River. It is part of the state of Pará. 
Marajó has a land area of 40,100 km² (15,500 sq mi). That is similar in size to Switzerland. The island is almost completely surrounded by fresh water. Large parts of the island are flooded during the wet season because of higher water levels of the Amazon River.
The most important towns are in the southeast of the island: Soure, Salvaterra, and the largest city, Breves.