Kanchanaburi is a town and a province in west central Thailand. It is bordered by Burma, now Myanmar, to the west. Kanchanaburi is the site immortalized by the movie The Bridge on the River Kwai, and the still-standing bridge is a major tourist attraction. You can take a train along the "Death Railway": across the bridge and a little further along sections of rail that were built by POWs during World War II. There is a perverse annual sound and light show which recalls the terrifying bombing of the area by the Allies, flying from Burma. There are also large graveyards filled with almost 10,000 white crosses which memorialize the farang POWs who died building and rebuilding the bridge.
It is odd, though I suppose rather canny in a mercenary way, that the Thai have turned this terrible place into a tourist site, as the whole Japanese occupation of Thailand during World War II is an episode most Thai would rather forget. While Malaya and Singapore were forcibly taken by the Japanese - and rather hastily abandoned by the British - Thailand, a non-colonized constitutional monarchy, chose instead to allow a peaceful occupation. The Thai have long felt a kind of kinship with the Japanese, the only other Asian kingdom to have avoided colonization, and the royal families have respected and maintained close ties with each other. At the outset of World War II, many Thai were attracted by the idea of an Asia controlled by Asians and welcomed the Japanese offensive into Asia.
Of course, the reality was that the Japanese considered themselves superior to the Thai, and annexed Thailand for their own ends. They used Thailand as a bulwark against the British in Burma, and became particularly well-established in Kanchanaburi, on the banks of a river which, once forded, allowed them access to Burma. That's why the bridge was so crucial to the Japanese, and why so many Allied lives were lost destroying it.
As the war went on, it became clearer to the Thai that they made the wrong choice in supporting the Japanese. However, in the aftermath of the war Thailand was not punished to anything like the extent that Japan was. It helped that a group of pro-American Thai had been stationed in Washington and provided with the means to make and distribute "Free Thai" propaganda (radio broadcasts, leaflets, etc.) in Thailand to counter the Japanese control of the Thai media. These pro-American Thai moved back to Thailand after the war and established a new government; the pro-Japanese faction was disgraced and drummed out of power.