The Khwae Yai River, also known as the Si Sawat, is a river in western Thailand. It has its source in the Tenasserim Hills and flows for about 380 kilometres through Sangkhla Buri, Si Sawat, and Mueang Districts of Kanchanaburi Province, where it merges with the Khwae Noi to form the Mae Klong River at Pak Phraek.

The bridge on the river Kwai, that many people know from the 1957 movie with the same name or from the book by Pierre Boulle is part of the infamous Death Railway, built during World War II from 1942 to 1943. The railway connected Kanchanaburi in Western Thailand with Rangoon in Myanmar, called Burma back then, and was about 415 kilometers long. On both ends construction began in June 1942 working towards each other. In October 1943 the two sides met, finishing the railway.

The Kanchanaburi War Cemetery is the main prisoner of war cemetery for victims of Japanese imprisonment while building the Burma Railway. It is on the main road, Saeng Chuto Road, through the town of Kanchanaburi, Thailand, adjacent to an older Chinese cemetery.

This small museum, opened in 1977, mostly focuses on the terrible ordeals of the POWs who built the Death Railway. Their harsh living conditions are shown in many original photos, letters and drawings from that time as well as personal effects and war relics, including an unexploded Allied bomb dropped to destroy the bridge. One of the three galleries is built from bamboo in the style of the shelters (called attap) the POWs lived in.