Kanchanaburi

Kanchanaburi guarded western approaches to Siam through the Three Pagodas and Bong Ti passes. Its older town stood at Lat Ya near Khao Chon Kai, where the river and surrounding hills helped block armies moving toward Suphanburi and Ayutthaya. The fighting of the late eighteenth century made this frontier particularly important to the Bangkok kings.

The town subsequently shifted downstream to Pak Phraek. Besides defence, river transport helped explain the choice: the old upstream position involved difficult rapids, while Pak Phraek offered easier commercial communication with Ratchaburi. Rama III ordered permanent walls and fortifications in 1831. The enclosure originally had eight gates, including two passages through fortifications. A red-sandstone inscription preserved near the city-pillar shrine records the building of the town, forts and walls, together with temple construction and repairs under its governor. These remains connect the new river town's commercial advantages with its continuing role in the kingdom's western defence.