Text & map by Tricky Vandenberg - July 2010 Review April 2013
(Extract of a begin-20th century map)
Khu Mai Rong or translated the "Moat of the Crying Wood", was situated off Ayutthaya's city island in Tha Wasukri sub-district. The man-made waterway split off on the northern side of the old Lopburi River (presently renamed Khlong Mueang) near Wat Phanom Yong and ran about half a kilometer inland.
Khlong Khu Mai Rong contained the landing of the barges. There were 20 barge houses adjacently situated, from the mouth of Khlong Khu Mai Rong to Wat Choeng Tha. The name of the canal was probably derived from the creaking of the wood from the wooden boats.
A land market was held behind the Dock of Royal barges in former times. Talat Wat Khu Mai Rong was one of the 32 land markets outside the city of Ayutthaya. The name of the marker suggests that there must have been once a temple in the vicinity of this canal called Wat Khu Mai Rong, though no traces of the latter has been found as yet. 
At the mouth of Khu Mai Rong there was one of the four primary floating markets of Ayutthaya. 
 Athibai Phaenthi Phra Nakhon Sri Ayutthaya (Description of Ayutthaya) with a foreword of Phraya Boran Rachathanin - edition 2 and Geography of Ayutthaya (2007) - page 94.  Markets and Production in the City of Ayutthaya before 1767: Translation and Analysis of Part of the Description of Ayutthaya - Chris Baker - Journal of the Siam Society, Vol. 99, 2011 - page 51.