The Pará River (Portuguese: Rio Pará) is the southern arm of the mouth of the Amazon River. It flows round the west and south of the island of Marajó. It takes some water from the main Amazon, however much of its power comes from the Tocantins River flowing from the south. The state capital of Pará, Belém, is located on the south bank of the river. It is approximately 40 miles long.