Japanese Railway Engineer Futamatsu describes his wonderment and fascination when he first glimpsed the limestone outcropping at what he calls Arrow Hill and today is known as the Wang Po. He was on a boat traveling upriver to visit the surveyors who were marking the TBR path. He says that he immediately was driven to make sketches of the trestle that would have to be built to circumvent this obstacle. About 50 Kms farther back, at Khoa Poon (near the current Chung Kai CWGC cemetery), the engineer teams had to make to small ‘cuttings’ through similar limestone, but this was the first major obstacle that the TBR encountered at about the 111 Km mark. Records say that this 400 meter multi-level trestle was completed in about two weeks by 2000 British POWs and romusha laborers.
Since the portion of the railway beyond Kanchanaburi was reopened in 1957, the Wang Po stop has become one of the most popular for the tourists. The daily trains, carrying almost exclusively tourists, continue on for another 10 Kms or so to Nam Tok before returning to Bangkok via Kanchanaburi. Rather than ride to Nam Tok many tourists get off at Wang Po and explore the market place, the trestle, the nearby cave which today contains Buddhist statues but was used by the Japanese as a shelter and for storage. Certainly, this trestle / viaduct is one of the most photographed places in all of Thailand.
The IJA Engineers were very experienced at railway construction. They were less confident in the workers that they were supervising. Given the slave-like status of the workers, the Engineers were constantly on the lookout for sabotage. It is said that after the completion of this trestle, some POWs were placed on a flat car that was pushed (not pulled) by a locomotive. This was the Engineer’s way of testing the integrity of the structure before it was placed into use.