Island in the Amazon River delta, Brazil.
The world's largest fluvial island, it is 183 mi (295 km) long and 124 mi (200 km) wide, with an area of about 15,500 sq mi (40,100 sq km). The main flow of the Amazon passes north of Marajó, but numerous narrow channels direct part of its water into the Pará River , an estuary that separates the island from the mainland to the south. Archaeological remains in the eastern savanna are similar to those of pre-Columbian Andean civilization .