Close to the Death Railway Bridge, at this eclectic museum you'll see trains, Japanese motorcycles, anchors and old helmets, plus a great view of the bridge: the tower in the northwest corner is the best viewpoint. Only about half the exhibits are about WWII; other displays include ancient pottery, record players, paintings of many Miss Thailands and a display case warning of the dangers of alcohol and cigarettes. Between the two buildings is a stupa with coloured bowls decorating its exterior.
While it's well-intentioned, the museum's dispersed (and sometimes context-free) displays have limited educational value; it shouldn't be your first stop for understanding Kanchanaburi's wartime history.
Also note that despite the misleading signs, this is not the JEATH museum.