The so-called "Death Railway" and its most famous section - depicted in the film, The Bridge over the River Kwai - was constructed during WWII to link Bangkok and Rangoon as Imperial Japan aimed to conquer and connect the whole of Asia.
Dutch, British and Australian prisoners of war were kept in dreadful conditions and 13,000 died building the railway, along with many more indentured Asian labourers.
Rajan Datar traces the railway's dark history and discovers new plans to unite South East Asia by rail.
Get in touch with Fast Track via
And follow us on
Watch Fast Track on the BBC World News channel on Saturdays at 04:30, 13:30 and 19:30 GMT or Sundays at 06:30 GMT.