Thale Chup Son
In the past, Thale Chup Son was a large natural lowland basin, connected to the slightly higher-located Phrommat fields (1) in the west, that amassed rainwater. Especially in the rainy season, water flowed from the Khao Sam Yot mountain range and drained into this lowland, forming a shallow lake.
King Narai ordered the construction of a large embankment to divert the stream from Thale Chup Son, passing it through a baked-clay pipe to the Rachaniwet Palace in Lop Buri. A mound remains. The Khmer likely constructed the Thale Chup Son freshwater reservoir and its soil dike in the 13th century. Its name is associated with the legend of Rama dipping his sacred arrow into the water. The area is associated with white marl deposits (2) and the traditional production of ‘din so pong’ (ดินสอพอง), a type of white mineral powder. The reservoir is now dry.
The freshwater reservoir was completed in 1684 CE to provide a continuous supply of fresh water to the Rachaniwet Palace, located 4 km southwest along the Lopburi River. The sloping ground from the low range of hills to the east formed a natural depression and served as one side of the reservoir embankments. On the south and west, a heavy earthen embankment enclosed the reservoir, about 7 km long and around 4 meters high, while the area available for water storage was roughly 2.5 square kilometres. These embankments are now part of Roads No. 3013 and 3016. The probable depth of the water, when the tank was full, must have been around 3 meters, deeper in some places and less in others. [5]
At present Thale Chup Son is no more, and the area is occupied with residences and many ponds, the latter the last witnesses of the old reservoir. We can still see the steep slopes dropping from the two roads into the low-lying area, which was once the bottom of the reservoir.
Guy Tachard, a French Jesuit missionary, described the lake as follows:
“At a league from Louvo this Prince has built a very roomy Palace. It is surrounded by brick walls fairly high. The interior is made of wood only. The place is very pleasant on account of the natural situation. There is a large stretch of water which makes of it a peninsula, and on this water the King of Siam has built two frigates with six small pieces of cannon, on which this Prince takes pleasure in going about. Beyond this canal is a forest, 15-20 leagues in extent and full of Elephants, Rhinoceros, Tigers, Deer and Gazelles.” [6]