River Kwai Bridge on the Death Railway , Kanchanaburi, Thailand

The most famous portion of the death railway is Bridge 277, "the bridge on the River Kwai", which was built over a stretch of river which was then known as part of the Mae Kong.  The greater part of the Thai part of the route followed the valley of the Khwae Noi River  (Khwae: branch or tributary; Noi: small; Khwae is frequently mispronounced by non-Thai speakers as "Kwai", the Thai word for water buffalo). This gave rise to the name "River Kwai" in English. In 1960, because of the discrepancy between fact and fiction, the part of the Mae Klong which passes under the famous bridge was renamed as the Khwae Yai(English "big tributary").

Internationally  famous, thanks the several motion pictures and books, the black iron bridge was brought from Java by the Japanese supervision by Allied prisoner-of-war labour as part of the Death Railway linking Thailand with Burma. Still in use today, the bridge was the target of frequent Allied bombing raids during World War II and was rebuild after war ended. The curved spans of the bridge are the original sections. A daily train is still following the historical route from Kanchanaburi to Nam Tok Railway Station.