The closest airport is in Ubon Ratchathani, 70 kilometres to the east of Si Saket.
Si Saket is located on the Northeastern line, with seven daily trains departing from Bangkok between 05:45 and 20:30. Fares run from 87 baht for a hard third-class seat up to 631 baht for an air-con sleeper, with decent second-class soft seats going for around 200 baht.
In Si Saket, trains run back towards Bangkok at 08:00, 09:50, 15:30, 17:55, 19:05, 19:30 and 20:30. These should stop at Surin, Buriram, Nakhon Ratchasima (Khorat) and Pak Chong (Khao Yai).
Trains run to Ubon Ratchathani at 02:20, 05:10, 06:20, 07:10, 08:55, 13:20, 15:50, 17:00 and 19:00. There are also a few local trains between Ubon and Khorat that stop at smaller towns.
Si Saket’s small bus station is located to the south of town off Kuang Heng Road, 1.5 kilometres south of the train station. Samlors, motorbike taxis and a few meter taxis can take you uptown. Fares include:
Bangkok (Morchit): Buses from a few different companies run often from 03:30 to 22:00. There are flurries of departures from 08:00 to10:00 and 17:00 to 20:00, but the only midday bus that we found departs at 13:00. Fares range from 320 to 500 baht depending on class; the most common first-class buses with toilets cost around 400 baht. The trip takes around nine hours and many of these buses can drop you in Surin, Buriram or Khorat.
Ubon Ratchathani: Minibuses depart at least once an hour from 06:00 to 18:00, cost 50 baht and take an hour. Many regular buses from Bangkok and Khorat also stop in Si Saket on their way to Ubon. If heading to Mukdahan, Nakhon Phanom or the Chong Mek border crossing to Southern Laos, transfer in Ubon.
Surin: Minibuses depart hourly from 06:00 to 18:00, cost 70 baht and take 1.5 hours. These can drop you near the Sa Kamphaeng Yai and Sikhoraphum Khmer ruins. If heading to the Cambodia border crossing at Chong Jom, transfer in Surin.
Khorat: Departs at 06:45, 08:15, 16:30, 17:30, 18:30 and 20:30, costs 350 baht and takes around five hours. If heading to Phimai, Khao Yai or just about anywhere in Central or Northern Thailand, transfer in Khorat.
Nong Khai: One daily bus departs at 08:30, costs 412 baht and takes around nine hours. Also services Khon Kaen and Udon Thani.
Kantharalak (closest city to Khao Phra Wihan National Park): Local buses run hourly from 06:00 to 18:00 and cost 50 baht.
Khun Han (for Wat Lan Kuad): Local buses depart hourly from 06:00 to 18:00 and cost 40 baht.
Si Saket is a fairly compact city that’s conducive to walking. There are also plenty of old-fashioned pedal-powered samlors, motorbike taxis and a few regular meter taxis. Motorbikes can be rented at Srilamduan Hotel to the east of town. Alternately, the Cuckoo’s Nest has one manual gear motorbike that may be available for rent.