The Meteuk Thmda River lies on the far side of the Cardamon Mountains near the border with Thailand. You will reach here if you continue on National Road 55 from Thma Da Waterfall.
It is another great spot for a freshwater swim in the river. The water runs fresh, cool and clean straight from the mountains. The shallow water runs over rocky rapids. It is a popular spot for locals to bring a picnic or barbecue, swim and fish.