Text by Tricky Vandenberg - November 2009
Khlong Pratu Khao Pluak (also called Khlong Pratu Jin in the southern stretch) connected the old Lopburi River (present Khlong Muang or City
Canal) in the north with the Chao Phraya River in the south. The canal had its northern mouth at Pratu gate. The canal lies in the present Pratu Chai
district of Ayutthaya.

The north-south canal was filled in last century and at present inexistent, with the exception of a small stretch of water between
Wat Tha Sai and Wat
Rachapraditsathan near Pratu Khao Pluak. The latter was in fact at the same time a water gate and a fortress (Pom Khao Pluak). Traces of the
fortress and the water gate (Pratu Khao Pluak) can still be seen in situ. Wat Tha Sai was an  important ferry crossing point to the landing of
Wong Khong on the opposite side of the river.

There were six bridges crossing Khlong Pratu Khao Pluak - Pratu Chin.

The most northern bridge was
Saphan Chang or the "Elephant Bridge" and connected the two sides of Elephant Street. The bridge was made of
laterite (sila laeng). The foundations of this bridge were dismantled in the reign of Rama III and the laterite brought to Bangkok to be used for the
foundations of the largest chedi of Siam at Wat Sakae (present Wat Saket) in Bangkok. (The large chedi collapsed during its construction process
because the soil was to soft and swampy to support the heavy building. The remains of this chedi were remodeled in the reigns of Rama IV-V, to
become known as Phukhao Thong or the "Golden Mount", a popular tourist spot in Bangkok). There are no more traces of the foundations of the
Elephant Bridge.

The second bridge was
Saphan Pa Than, made of brick.

The third bridge was
Saphan Lad. This cross-over was made of wood and stood in the vicinity of Wat Lad, hence its name. No traces of the bridge

The fourth bridge was
Saphan Chikun, made of brick and located in the area of the Brahmin shrines.

The fifth bridge was
Saphan Khun Muang Jai also made of wood identical as Saphan Lad. It stood in the vicinity of Wat Khun Muang Jai, hence
its name. No traces of the bridge remains.

Finally, the most southern bridge was
Saphan Talad Jin, made of brick.

All the above bridges are visualized on Johannes Vingboons' painting named "Afbeldinge der stadt Iudiad Hooft des Choonincrick Siam", a water
colour of 42 cm by 63.5 cm being part of the Vingboons atlas published around 1665. The painting is very detailed, which makes it possible to
identify the bridges.