Day trips from Bangkok: which are worth the journey?

9 day trips, ranked on whether they repay the hours on a train or bus. 3 are clearly worth it. Every page has the fastest way there, a plan for doing it in one day, and parking if you drive.

#	Day trip	Verdict	Reality	Getting there
1	Ayutthaya	Worth it	81	About 64 km north of Bangkok; trains roughly hourly, ~1.5 hours, from ฿20 in 3rd class (check whether your train leaves Hua Lamphong or Krung Thep Aphiwat); then bike or tuk-tuk between sites
2	Bang Krachao	Worth it	76	MRT Khlong Toei or QSNCC, then short taxi (or ~30 min walk) to Wat Khlong Toei Nok pier and a 5-min ferry; allow ~45–60 min from Siam
3	Khlong Lat Mayom	Worth it	71	No rail station nearby: BTS Silom line to Bang Wa then ~฿100 taxi, or a metered taxi from central Bangkok (~25 min on a quiet Sunday morning, ~฿175); ~30–45 min from Siam/Rattanakosin depending on traffic
4	Erawan Museum	Worth it if…	69	BTS Sukhumvit line to Chang Erawan, then a short taxi or motorbike taxi; ~30–45 min from central Bangkok, plus BTS time from Siam
5	Erawan Falls	Worth it if…	65	About 3 hours from Bangkok: van from Mo Chit to Kanchanaburi (~2 h), then the hourly local bus (08:00–17:00, ~1 h, ฿45) to the park; or a long day tour.
6	Khao Yai	Worth it if…	65	Bus from Bangkok to Pak Chong about 3 hours, then a songthaew to the gate (km 167 on Highway 2 turn-off); no public transport inside the park, so most visitors drive, hire a driver or join a tour
7	Maeklong Railway Market	Worth it if…	61	~70 km from Bangkok.
8	Ancient Siam	Worth it if…	54	BTS Sukhumvit line to Kheha (end of the line), then 5–10 min by taxi/Grab; free weekend shuttle from Kheha reported.
9	Damnoen Saduak	Skip it	25	About 100 km southwest of Bangkok: minibus from the Southern Bus Terminal (Sai Tai Mai), ฿80 each way, roughly 2–3 hours with traffic; most visitors come on a tour combined with Maeklong Railway Market