At first glimpse, Hualamphong station in Bangkok could be one of Europe's great railway cathedrals. Passengers proceed through a pillared portico into a giant atrium, topped with a huge curved roof which stretches away into the distance, where it finally ends in a screen of stained glass. Closer at hand, the congregation is halted by booking offices which bisect the nave, where enquiring passengers are supplicants at the altar of rail, seeking a more prosaic kind of communion. Behind them, the monks sit contemplatively in their pews, and in the side aisles a handful of the faithful lie prostrate on the floor.
But this is not Europe, nor is it a holy building: these monks are shaven-headed and saffron-robed, and they are contemplating their Sudoku, not their holy texts, while waiting for the slow train home. As for the prostrated few, they have not been overwhelmed by divine revelations but by what they've just ingested, whatever that may be.
No, Hualamphong is no cathedral, and yet, because this is Bangkok, it can still be a gateway to heaven or hell for anyone who passes through.
For the Thais from upcountry, the station represents the beginning of a new life, good or bad. When the upcountry harvests fail, the sons and daughters of rice farmers' arrive here, bleary-eyed, on the overnight trains, to be swept up by those seeking cleaners for hotels, drivers for taxis, girls for massage parlours, hostesses for bars.
But for me, crossing the nave on that particular afternoon led by dancers and drummers, it was the beginning of a particularly Thai adventure that was to travel in the other direction, into the cultures and landscapes beyond the city that make Thailand so distinctively Thai. An adventure made possible by the most glamorous train in South-east Asia which stood, green and gleaming, alongside platform three.
The Eastern & Oriental is already a regular visitor to Hualamphong on its bread-and-butter journey between two capitals, Bangkok and Singapore. But like its luxurious European relative, the Venice Simplon-Orient-Express, it is diversifying with a selection of new, more exploratory itineraries that get closer to the fabric of South-east Asia, but without losing the E&O style. Today, it was embarking for its pioneering six-night "Epic Thailand" itinerary.
Thailand makes ideal subject matter for closer examination. Of all the South-east Asian countries, it is easily the most exotic: in food, in religion, in music, in language, and it is a place where the fascination is in the detailing, in the sweep of a temple roof, the delicacy of the carved fruit, the offerings on every street-corner shrine.
The train reflects that attention to detail, both in its sumptuous interior – intricate rosewood marquetry on the walls, orchids in the cabin, frangipani flowers in the bathroom, an immaculate cabin attendant who polishes your shoes without you asking – and in the way it plans its itineraries.
For example, on our first full day out of Hualamphong, we'd set off into lesser known eastern Thailand (Isaan) to descend on a village called Maichanmuak, a tiny community which had rarely seen Western tourists before. That's not to say the ground hadn't been thoroughly prepared: half the village was waiting in the temple to take us through the bai sii ceremony, during which threads were tied around our wrists by the village elders to ensure that we would have protection from evil spirits on our journey.
And so that we could express our gratitude for being allowed to participate in something so intimate to them, the E&O had prepared gifts for us to give the elders in return, an exchange that made our presence on their territory feel less like an intrusion. Furthermore, in preparation for this whole adventure, the company had built a dedicated Western-style toilet just outside the temple. It was to remain in situ as a permanent legacy of our visit, and get used by E&O passengers just twice a year (the next departure on the "Epic Thailand" itinerary is not until 30 October). The rest of the time it was to be a porcelain throne for a rice-farming people who described their normal lives as "back to the sky, face to the ground, forever" to sit upon, and contemplate the joys of life in the West.
Back in our own travelling throne, the train, it was clear that the flat, dry and infertile Isaan is not obvious tourist territory. Yet its present status as a Thai region papers over its past as part of the territory ruled by the Khmer dynasty, the builders of Angkor Wat. So Isaan has its own network of Khmer temples, too, which were once part of the Angkor masterplan.
The first one we visited was introduced to us after lunch on the train by a rather dry lecture on Khmer Hindu culture and temple design. A couple of hours later, dutifully disembarking for Prasat Sikhoraphum and prepared to be enthusiastic about shiva carvings and decaying brickwork, we found we'd been the patsies in a gentle deception: in fact this was an exotic surprise party, and awaiting us were Thai dancers, musicians, chefs and a couple of elephants who'd turned up dressed in the colours of E&O.
The pocket-sized temple itself – 11th-century and elegant – was actually really just a spectacular setting for the dancers to dance and the musicians to play. For the true temple devotee, this was possibly a bit frivolous, but it was balanced the following day by a visit to a far more dramatic and spectacular Khmer temple: Phanom Rung – a giant 12th-century shrine on top of an extinct volcano.
There it rose like something from the dawn of time, its stonework the colour of petrified autumn bracken, frosted with lichen, guarded by fearsome stone nagas (dragons) and surrounded by giant stands of bamboo. As if it wasn't already sufficiently Indiana Jones, its main axis has 16 doorways. Twice a year the rising sun shines directly through them all, watched by thousands of Thais, who make a special pilgrimage for the event.
After a couple of days on the train, life on board settled into a rhythm. Breakfast in the cabin, sometimes with that day's newspaper to read as the countryside slid by; an excursion, followed by lunch served in a choice of two restaurants, with a view of the sun glistening off the wet rice paddy fields. The train jogged while buffalo wallowed, among a parliament of bright white egrets. At one point we were overtaken by a man on a motorbike with two bamboo baskets of piglets, their pink flesh bulging out through the weave.
There would be a talk in the afternoon, or a new destination with another excursion, followed by some more travelling, with a lot of us ending up on the open-air observation car on the back, waiting for the sun to set. I'd had misgivings about the contrast between our luxury and the lives of those on the other side of the tracks; travel through the UK waving regally and clutching cocktails, and you'd be rewarded with a hail of stones. But the Thais seemed genuinely delighted to see us.
The evening's main event was a formal silver-service dinner of fusion European/Asian cuisine, while the train plunged into the night through rings of fire. (The farmers were burning rice stubble.)
It was like a succession of particularly exotic lunch and dinner parties. Just 60 passengers were on board: the E&O's normal occupancy of 130 is more than cut in half to give travellers on this extended itinerary extra space. So it was easy to mingle. My co-diners included a young French aristocrat with a penchant for bright red trousers; an American timber merchant with a fierce handshake that belied his 90 years; and a consular official from the Australian embassy in Pakistan.
The only problem with meeting so many people in quick succession is that you find yourself wondering, in mid-conversation, whether you've already said exactly the same thing to exactly the same people before. If I did, I apologise, and they were too polite to mention it.
Afterwards, we would decamp into the piano bar for a nightcap, where the energetic French chef with a Greek name, Jannis ("I was a little souvenir from my parents' holidays"), could sometimes be seen late at night, dancing exuberantly.
After a couple of days weaving our way through the Isaan, the train returned to the emerald carpet of Thai's irrigated central plains, and there it headed north for Chiang Mai. Thailand's second city is set 1,000 feet above sea level, so the early morning air chilled as the locomotives climbed. The vegetation began to falter in the thinner air, straggling weakly out of poorer soil. Banyan and monkey-pod trees were replaced by dry thickets of creaking bamboo, which harboured spindly, feathery-topped teak trees, old before they'd even been young. Finally a long tunnel, and then a longer descent, and we were there.
Chiang Mai is a relaxed place, the former capital of the Lanna kingdom. Its old centre (founded in the 13th century) is surrounded by a moat and crumbling city walls. It's a walkable city, with temples and handicrafts and adventure tours and restaurants and markets and bars, and none of the oppressive humanity of Bangkok.
Put on the map by backpackers, these days it is on the itinerary for mainstream tourists, too, but it still manages to feel intimate and distinctive in its network of sois or lanes. Between them, these sois cradle more than 300 temples, some of them seven centuries old, wheredevotees can do anything from having a massage to buying caged birds and releasing them to gain more merit in the afterlife.
Thanks to E&O's pixie dust, I'd chosen to try to get closer to Thai culture by spending a morning in one of these temples, talking to two monks about their daily lives. One was a former soldier whose life choices hadn't really worked out and was now seeking reincarnation, and the other a young Lao Buddhist who saw the temple as a way of completing his education. While we talked, I sat in the temple yard and tried to learn how to string together flower garlands for spirit offerings under the eagle eye of a matron in white, who chided me for pinching the petals too hard.
With only a day in the city, we passengers of the E&O were always going to be limited in what we could achieve. Back on board that evening, the consensus was that we were leaving Chiang Mai without having done it justice. But then there was still Lampang and the Khao Yai national park to look forward to.
In Lampang, we were taken to a timber merchant's villa that was supported on 116 teak pillars and looked airily out over summer lawns. And in Khao Yai, we took an early morning wildlife walk through the forest, seeing deer, gibbons and macaques. That was followed by lunch at a real Thai vineyard, the GranMonte. (Thai wine was a good effort, everyone concluded – but equally, it was splendid that we had vintages from more established wine-making countries on board.)
As we rumbled back southwards, with Bangkok's Hualamphong and the realities of life on the horizon once more, I went for a consultation with the palm reader who had just joined the train. I would live until I was 90, she said. I may have had bad knees and a bad back, but I was blessed with two children and a good wife. My life was good, she continued. Given my surroundings it was hard to disagree. One thing, though, she added: I needed to try harder to relax. Good point. So I went back to my cabin and asked Mr Thanasit, my gentlemanly cabin steward, if he wouldn't mind bringing me some afternoon tea.
Travel essentials: Thailand
* The writer travelled with Kuoni (01306 747008; kuoni.co.uk), which offers trips incorporating the Eastern & Oriental Express (0845 217 0799; orient-express.com) from £5,784. The price includes flights from Heathrow to Bangkok on Thai, transfers, three nights' room only at the Mandarin Oriental in Bangkok and six nights' full board aboard the train on the "Epic Thailand" journey.
* Bangkok is served non-stop from Heathrow by BA (0844 493 0787; ba.com), EVA Air (020-7380 8300; evaair.com), Qantas (08457 747767; qantas.co.uk) and Thai Airways (0844 561 0911; thaiairways.co.uk). For flights from UK regional airports try Emirates (0844 800 2777; emirates.com) or a wide range of other airlines.
* Tourism Authority of Thailand: 020-7925 2511; tourismthailand.co.uk
In the cheap seats: Budget rail in Thailand
Thailand has embraced the concept of train travel in recent years, with the latest offering a 100mph link between Bangkok airport and downtown. Also in the capital, there's a relatively new underground railway, and the longer-established elevated Skytrain. Both are invaluable in tackling a city whose traffic is appalling.
But these are operating at the sharp end of urban development. Far more typically Thai are the rackety-clackety long-haul train services that link Bangkok economically to the provinces. Typically, a second-class sleeper ticket from Bangkok to Chiang Mai costs 791 baht, or £17.20. A real travel bargain. You can easily emulate the journey of the Eastern & Oriental Express "Epic Thailand", by taking the main route east, towards the border with Laos (final destinations Nong Khai and Ubon Ratchachani), then back to Bangkok and north to Chiang Mai. Heading south, trains run to Surat Thani, a key terminus for ferries to the island of Koh Samui and for bus transfers to Phuket. Several southbound services continue to Had Yai. One each day crosses the Malaysian border to Butterworth, the station serving Penang.
These trains are cheap and safe, although usually late. Most are composed of second-class sleeping cars, where bunks are seats by day, and are unfolded and dressed with sheets and pillows by night. Usually these come in groups of four, sealed off by individual curtains, although if you want more privacy you can travel first class. All are air-conditioned apart from the restaurant car, which can become a bit of a drinking den in the evenings. Restaurant staff will bring food to your berth, to order.
Most people buy their tickets at the station a day or so before departure. Unless there's a particular Thai festival, there will usually be availability. Timetables and prices are online at the official site, www.railway.co.th. You can also book online through thailandtrainticket.com, and there's invaluable information from The Man in Seat Sixty-One's site, seat61.com/Thailand.