Train travel. Suspended in the rocking belly of the iron beast, with Thailand scrolling past your window—bridges, backyards, paddies, hills and the clang of level-crossing bells—there’s nothing quite like it, says veteran travel writer John Borthwick.

It all starts at Bangkok’s Hua Lamphong terminus, the heart of a rail web stretching from Nong Khai to Hat Yai. A throwback to the glory days of rail travel (it was built in 1916 by King Rama V, the monarch credited with protecting Thailand from colonization), this grand old dowager with its vaulted roof gives any journey a ceremonial sense of departure.

The night express to Chiang Mai is the classic Thailand rail trip. I board it for the 750-kilometer (465-mile) journey, ready to rock (quite literally) on Thailand’s narrow, one-meter gauge tracks. I’ve booked a four-berth compartment with upper and lower bunks in the popular, air-conditioned second class.

A snappily-dressed State Railway of Thailand inspector checks our tickets, followed by a caterer who takes meal orders. When my vegetarian option arrives, a Thai gent in the compartment laughs: “No spice, no meat, no fun. Monk food, I think.”