The Bridge on the River Kwai, (made famous by the omonymous film with Alec Guinness and William Holden and which won 7 Academy Awards in 1957) was a key strategic element for the Japanese war effort during WWII. The Japanese needed to build a railroad in record time between Thailand and India a and they used their war prisoners to do it.
Construction of the Thailand-Burma Railway began on September 16, 1942.
The Railway, was to transport 3,000 tons of supplies per day to the frontline troops in Burma. Much of it required high bridges cut through mountains and jungle. The human cost was incredibly high. The railway operated for just 21 months before it was crippled by Allied weapons,
The train runs daily between Kanchanaburi and the current terminus at Nam Tok going over the bridge and passing over the equally impressive Wampo Viaduct, also built by prisoners of war.
61,000 Allied prisoners of war are believed to have labored on the railway under impossible conditions, including 30,000 British, 18,000 Dutch, 13,000 Australian, and 700 American soldiers. 16,000 of those troops died, many of them from diseases like cholera, beri beri, malaria, and typhoid, Another 200,000 Asian laborers, mostly Thai, were forced to work on the railway. More than 80,000 lost their lives.