The parallel valleys of the Kwai Noi and the Kwai Yai, northwest of Kanchanaburi, are stacked full of great day-tripping opportunities, from the exceptionally beautiful Erawan Falls to the drama of a ride on the Death Railway and the pathos of the World War II museum at Hellfire Pass. There are Stone Age artefacts at the Ban Kao Museum, twelfth-century Khmer temple ruins at Prasat Muang Singh, the (controversial) opportunity to get up close to a tiger at the Tiger Sanctuary Temple and several good caves, including at Tham Than Lot National Park and the riverside Tham Lawa.
Many of these attractions are served by public transport, the train being an obvious option along the Kwai Noi valley as far as its Nam Tok terminus, with buses useful along both valleys. But train schedules are unreliable and bus connections can be time-consuming so many people either opt instead to join one of the many mix-and-match tours offered by Kanchanaburi agents or rent their own wheels for a day. Distances are not large, and there’s a handy connecting road between the two valleys just south of Nam Tok.