Ayuthaya is one of the old cities near Bangkok, Its a great place for a one day trip. Weekend Getaway Kinda place. Its like a mini Laos/Jogjakarta/Cambodia. All the structures are ancient and beautiful. You can find a lot of Buddha Idols here. A great place to get some great photos.There are trains that leave every half an hour from Bangkok (Hua Lampong) Railway Station. You can get a 3rd Class ticket just for 15Bhats. Its a 2 Hour Journey and quite a pleasant ride. You can buy fruits and drinks on the train. No need for reservation, you can get the tickets at the station on the spot.Once you reach there make sure you get a bike on rent, its available right outside the railway station, will it will cost you around 250 bahts for a day. Cheap! Dont forget to ask for a map!