Mae Nam Chao Phraya

River, Thailand. Flowing south from the highlands on the country's northern border to the head of the Gulf of Thailand near Bangkok, it is some 225 mi (365 km) long and is Thailand's principal river. It is important for the transport of the country's exports. It also forms a highly productive agricultural valley. The name strictly applies only to the river's lower course, which begins at the confluence of the Nan and Ping rivers and is 140 mi (225 km) long.

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