Chao Phraya River. The Chao Phraya River is the major river in Thailand, with its low alluvial plain forming the centre of the country. It flows through Bangkok and then into the Gulf of Thailand. Etymology On many old European maps, the river is named the Mae Nam (??????????????????), the Thai word for "river" (literally, "motherly water"). Irish surveyor and cartographer James McCarthy, F.R.G.S., who served as Director-General of the Siamese Government Surveys prior to establishment of the Royal Thai Survey Department, wrote in his account, "Mae Nam is a generic term, mae signifying "mother" and Nam "water," and the epithet Chao P'ia signifies that it is the chief river in the kingdom of Siam." Herbert Warington Smyth, who served as Director of the Department of Mines in Siam from 1891 to 1896, refers to it in his book first published in 1898 as "the Mae Nam Chao Phraya". In the English-language...