Arriving in Kanchanaburi town
Official Transport Company material documents services between Bangkok and Kanchanaburi province, including a route continuing to the Three Pagodas Pass. The Bangkok terminal and final stop depend on the service, so check the ticket rather than following an undated terminal claim.
For a town stay, confirm whether the drop-off works for the River Kwai bridge area or the central bus station. A cheap ticket can still require a taxi or songthaew at both ends.