Amazing Thailand
Land of smiles
Boat transportation to Ayutthaya
You can also get to Ayutthaya from Bangkok by cruise boat.
The downsides of going by boat is the time taken (a whole day), the cost and the fact that there are no scheduled services - tourists need to book in advance. Stops are at Ko Kret and Bang Pa-In, and overnight tours are available.
Usually people only use this option as a privately arranged tour, and an overnight trip to Ayutthaya on an old teak barge is a charming and luxury experience