There's actually no river Kwai (buffalo), it's the Mekong River. The Thai government actually renamed a small section of the Mekong "Kwai" for tourists after the movie caused people to go to Kanchanaburi looking for it.
Also, that section of the bridge that's shown in the picture was used in the movie Casualties of War in the scene where the Vietnamese girl the solders kidnapped was killed.
Also, that section of the bridge that's shown in the picture was used in the movie Casualties of War in the scene where the Vietnamese girl the solders kidnapped was killed.