Thorn Tree travel forum

1

if you want to go by train, best way from Kachanaburi if you don't want to go back to Bangkok is to take a bus to Supanburi and then another bus to Ayuthaya. You can get the train ticket a few days before either at a Bangkok train station Ayuthaya-Chiang Mai to be on the safe side in case it's booked up.

you'l need a full day to do the sights in Kachanaburi,see the sights, and if you start early you can also get to look around Ayuthaya for a while before joining the night train later.

can't post links here ATM, too slow, but just google kanchanaburiinfo.com for the bus timetables to Supanburi. It's easy.

2

As above you could avoid going back to Bangkok and if you had your timing right it would be the potentially quickest option. Otherwise you could do better to just backtrack those few hours since there are so many more services going that way. In the time "saved?" trying to do it slightly more direct you could easily just take a train/bus to Bangkok and jump on the next thing going north. At any rate it's not possible to continue north straight out of Kanchanaburi as that area is very rugged and undeveloped with little or no roads to speak of. Hope this paints the options well enough.