It empties after 231 kilometres[1] into the Gulf of Thailand at the northeastern tip of the Bay of Bangkok.

[4]: 302, 309 Its name "Bang Pakong" is believed to be distorted from the word "Bang Mangkong" (บางมังกง), refers to "place of Mangkong", for "Mangong" is Thai word meaning long whiskers catfish (Mystus gulio), a species of brackish water catfish that used to be found in this river.

Excavations from archeology sites in the former city revealed that it was inhabited from the 600s to the 1000s, and had ceramics imported from the Tang and Song dynasties, and early Islamic turquoise-blue glazed earthenware jars from either Persia or lower Mesopotamia.

Sri Phalo served as a stopping point for Khmer, Vietnamese and Chinese barques before they ventured into the Chao Phraya river.

As a result of its economy declining, the inhabitants of Sri Phalo relocated south to Bang Pla Soi along the Gulf of Thailand.