Bangkok to Ayutthaya

Almost every train heading north and northeast from Krung Thep Aphiwat stops at Ayutthaya, so there are about 16 fast departures a day, the morning ones at 06:10, 07:10, 07:30, 07:50, 08:45 and 10:35, the afternoon one at 14:15, and a string of night trains from 18:40. The ride takes 50–80 minutes and a third-class seat costs about ฿20, bought at the station on the day; Ayutthaya is a short hop on these long trains, so seats are sold close to departure rather than weeks ahead. Second-class air-con seats cost more, and the expresses (Nos. 7 and 21) are second class only. The MRT Blue Line stops under the station.

Bangkok Connex is the new option and the one I'd take. Launched on 1 August 2026, it's a direct, air-conditioned service on refurbished Japanese railcars that runs Krung Thep Aphiwat to Ayutthaya in 75 minutes with stops at Don Mueang, Rangsit and Bang Pa-in, for ฿50 on its launch fare (to 31 October 2026). It leaves at 09:05 and 18:15 every day and at 05:15 on weekdays, and comes back from Ayutthaya at 14:40 and 19:45, plus 06:50 on weekdays. Seats are unreserved and tickets are sold only at the station, from about two hours before departure; the 09:05 has filled up on busy days, so arrive early. One timetable lists the 19:45 return as weekdays only, so check it at the station.

The slower ordinary trains still leave Hua Lamphong, the old station near Chinatown, about 11 times a day from 04:15, and take 1.5–2 hours for about ฿15–20. They're handy if you're staying near Chinatown or the river.

Ayutthaya station is on the east bank, across the river from the island where the ruins are. Walk from the station to the river landing and take the ferry across for ฿10 (฿20 with a bicycle); the last boat is around 17:30. Bicycles rent for ฿60–100 for the day on the island side, or a tuk-tuk from the station to the park is about ฿150.

There's no charge to enter the historical park itself; you pay at each major temple, ฿80 for foreign visitors, or buy the combined ticket for ฿300, which covers seven sites, among them Wat Mahathat (the Buddha head in the tree roots), Wat Ratchaburana, Wat Phra Si Sanphet, Wat Phra Ram and Wat Chaiwatthanaram. Most sites open 08:00–18:00, Wat Mahathat until 18:30. Cover shoulders and knees, and bring water and a hat; the sites are spread out and shade is patchy.

Yes, Ayutthaya is an easy day trip. Take the 09:05 Bangkok Connex (or a morning rapid at 07:10 or 07:50), cross on the ferry, rent a bicycle and start at Wat Mahathat, then Wat Ratchaburana and Wat Phra Si Sanphet, which are close together in the middle of the island. Have lunch, then ride or take a tuk-tuk out to Wat Chaiwatthanaram on the far bank, the most photogenic of the ruins. For the trip back, the 14:40 Bangkok Connex suits a half day, the Chiang Mai day train No. 8 leaves Ayutthaya at 16:48 for Krung Thep Aphiwat at 17:40, and the 19:45 Bangkok Connex lets you stay for sunset at Wat Chaiwatthanaram. If you'd like a slower visit, stay a night; the town is quiet once the day-trippers leave.