The Prachinburi River — a tributary of the Bang Pakong, itself part of the Pa Sak drainage — runs through the centre of the provincial capital, giving the town its most attractive feature. The riverside strip retains a handful of colonial-era shophouses and administrative buildings from the late 19th century, when Prachinburi was a trading post of some significance on the route east from Bangkok.
The waterfront is pleasant to walk in the early morning or evening, when the light is soft and the river traffic — small fishing boats, occasional long-tails — is at its most active. A riverside promenade runs along the main bank near the centre of town. The area around the old market (talat kao) and the clock tower is the most characterful part of town, with a few traditional wooden houses surviving among the newer concrete blocks.
The river also marks the informal boundary between the old administrative core and the newer commercial quarter. If you are based in Prachinburi town, an early-morning walk along the river before heading out to the parks or ruins is a good way to get a feel for the place.