By ship
Cruise boats run up the river from Bangkok, often stopping at Ko Kret and Bang Pa-In along the way. You'll need to book in advance as there are no scheduled services, just trips for tourists. It's a fairly lengthy trip at least one whole day and some of the larger boats offer pricy overnight tours.
Travelling by boat to Phra Nakhon Si Ayutthaya is popular among foreigners since it does not only reveal the beauty as well as lifestyle of the people on both sides of the Chao Phraya River, but also reflects the life in history at the time of the Ayutthaya Kingdom when the Chao Phraya River served as a channel of transportation in trading with foreign countries.
By bus
Buses operate every 20 minutes or so from Bangkok's Northern Bus Terminal Moh Chit* directly to Ayutthaya despite what locals say, the last bus leaves at 6PM. First class air-con buses charge 50 baht. This trip is scheduled to be around an hour and a half, but allow at least two hours for the trip since the buses stop rather frequently and there are often jams on the roads out of/into Bangkok.
To get to Northern Bus Terminal, take to Moh Chit BTS Station. Upon exiting gantry gates, cross the bridge on the right to go to bus-stop, and take bus service 3 or bus service 77. air-con buses charge 12 baht, non air-con buses charge 7 baht. Bus ride is about 10 - 15 minutes and the Northern Bus Terminal destination is the last stop for the bus services. However, buses do not stop in the Northern Bus Terminal, but at the bus stop across. Cross the bridge to get to the Bus Terminal.
Bus service 3 runs also near Khao San. It goes by Thanon Chakrabongse Rd which is a street on the Western end of Khao San. Whole trip to Northern Bus Terminal from here takes in morning around 1 hour. Getting back in evening can take longer due to traffic.
Also you can take a minivan from the Victory Monument direct to Ayutthaya. Takes ~1 hour and costs 100 baht. Minivans depart every 20 minutes or so.
The buses are from 4:30AMâ7.15PM. For more details, please call Tel. 0 2936 2852-66 or see the website (http://www.transport.co.th) and Ayutthaya Bus Terminal, Tel. 0 3533 5304.
In Ayutthaya, the central BKS bus station is on the south side of Thanon Naresuan next to the Chao Phrom Market. songthaews to Bang Pa-In also leave from here. Some 1st-class buses to Bangkok, however, leave from the north side of the road some 500m to the west, on the other side of the khlong canal; the queue for air-con buses is easy to spot.
From Kanchanaburi, take a local bus from the main bus station to Suphanburi for 45 baht 2 hours, then another local bus to Ayutthaya for 40 baht 1.5 hours. A taxi from Kanchanaburi costs 2000-2500 baht 2 hours.
There is also a central bus station east of town serving northern destinations. It can be reached by songthaew - ask around to find the appropriate stop.
By train
The cheapest and most scenic way of reaching Ayutthaya is by train. It regularly departs from Bangkok's Hualamphong Train Station and stops in Ayutthaya. The trip takes about 2 - 2.5 hrs depending on the type of service. Second class seatsA/C cost 245 baht, third class is just 15 baht ! no reservations and seats are not guaranteed. Fares in July 2011. Check time table here: (http://www.railway.co.th/...) note that fares listed on the Thai railways site are out of date and incorrect. Although in the past railway employees prefered not to sell 3rd class tickets to foreigners, as of 2011 the employees were explicitly offering 3rd class seats to western tourists as a standard option. Also note that some train stations for instance Bang Khen do not appear on the sites map, and that tickets may even be cheaper. If you have local friends, they may have some good advice.
The railway station is not on the island but across the river a short ferry ride away. Walk across the main road and down the small street straight ahead. Ferry boats run every few minutes and cost 4 baht.
By Minibus (Van)
Convenient minibus service can get stuck in traffic, but makes no stops like regular buses operates from the Victory Monument square in Bangkok. Take BTS Skytrain to the Victory Monument station, and go right on the elevated walkway - keep on it until you cross a large road, then descend - the buses are parked at the side side of the main traffic circle). The cost is 60 baht, takes around 1 hour ro 1 hour 20 min. It's quite convenient since you don't have to go to bus terminals nearby Mochit but the only problem is that the minibuses don't have much space to put big bags and have to wait until the car is fully filled.
Minibuses van from Kanchanaburi can be arranged by guesthouses or any tour operators for around 400 Baht October 2012. Most tour operators charge 400 Baht for a 2,5 hours drive. There is one tour operator charging 380 Baht, but this one is not recommended since it takes 5 hours to reach Ayutthaya. This one will pass Bangkok first.
By car
From Bangkok, one can get to Phra Nakhon Si Ayutthaya by various routes:
Take Highway No.1 Phahon Yothin via Pratu Nam Phra In and turn into Highway No.32, then, turn left to Highway No.309 to Phra Nakhon Si Ayutthaya.
Take Highway No.304 Chaeng Watthana or Highway No.302 Ngam Wong Wan, turn right into Highway No.306 Tiwanon, cross Nonthaburi or Nuanchawi Bridge to Pathum Thani, continue on Highway No.3111 Pathum Thani â Sam Khok â Sena and turn right at Amphoe Sena into Highway No.3263 to Phra Nakhon Si Ayutthaya.
Take Highway No.306 BangkokâNonthaburiâPathum Thani, at Pathum Thani Bridge Intersection, turn into Highway Nos.347 and 3309 via Bang Sai Royal Folk Arts and Crafts Centre, Amphoe Bang Pa-in, to Phra Nakhon Si Ayutthaya.
Take Expressway No.9 Si Rat Expressway via Nonthaburi â Pathum Thani and down to Highway No.1 via Bang Sai Royal Folk Arts and Crafts Centre, turn left into Highway No.3469 towards Bang Pahan and turn right at Worachet Intersection to Phra Nakhon Si Ayutthaya.
One can also contact a taxi for pick up at the international airport of Bangkok.For example: Car Service, phone: +66 0 2819 5390, email: [email protected]). Advance booking possible. ~1200Bahts one way.