With the steady ker-plunk of the wheels rotating on the track, the scenery changes from the vast green plateaus and round felt tent homes of Mongolia to the alpine forests and log cabins of Russia’s Siberia.

The Trans-Siberian Railway, the longest train line in the world, spans almost 6,000 miles and takes six days from Beijing to Moscow. For some tourists, it’s simply a way to get from Asia to Europe (or vice versa), while other passengers see it as an experience of a lifetime. “It’s something you feel you have to do,” said Jose Luis Sese, 39, from Zaragoza, Spain. “I knew it wasn’t going to be as exotic as it’s made out to be, but still, you have to do it because you’ve read about it. It’s a mythical trip.”

Mythical, maybe, but indeed, the trip gets monotonous at times. What compels passengers to take the long ride from one continent to another was something of a mystery to me, even though I’d signed on for the journey myself. Siberia is, after all, the place where the Soviets sent political dissidents and other persecuted citizens for punishment.

I bought my ticket in Beijing at a travel agency that specializes in trans-Siberian trips called – and this is no joke – Monkey Business (The Red House, Room 35, Chunxiu Lu, Dongzhimenwai, Chao Yang District, Beijing, P.R. China, 8610-659-6519, www.monkeyshrine.com). For the price of 761 euros (roughly $1,000), I got a ticket that allowed me to stop off in Ulaanbaatar, Mongolia, and Lake Baikal in Siberia; a tour guide and two nights in a homestay accommodation at the lake; and one night in a three-star hotel once we arrived, travel weary, in Moscow.

In recent years, tourists have begun to see the Trans-Siberian train ride as a holiday in itself, rather than just an inexpensive way for budget-minded backpackers to get between Asia and Europe, said Chris Stanley, the office manager at Monkey Business. “It used to be a ‘rat run’ – a way to get from Asia to Europe that was cheaper than flying. Over the years, the trend has been for tourists to stop off and see more.”

Tour companies recommend that tourists break up their journey at least once along the way – good advice, unless one wants to go without a shower for six days. I began in Beijing, and 30 hours, or 848 miles later, stopped off in Ulaanbaatar, Mongolia’s dusty capital, full of new buildings and cranes and surrounded by suburbs full of fenced-off felt tents. After a week at the Puma Imperial Hotel, just east of the capital’s government house (976-11-313043, www.mongolianpumahotel.com;r ooms $53-$110 a night), I boarded the train again and headed for Russia, 696 miles away. Thirty-six hours later – 11 of which were spent on the Mongolia-Russia border waiting on the train to clear customs and immigration – we crossed over.

At the bustling city of Irkutsk, a tour guide and driver from Monkey Business met me at the train station and drove me the two hours to Siberia’s Lake Baikal, the world’s largest freshwater lake, and an area that is inhabited by Buryats, a Russian minority descended from Mongols. My two-night homestay with a Buryat family was a nice reprieve from the train, and gave me insight into what it would be like to live in the middle of Siberia. The cabin had no running water or phone line, but hikes around the lake, hearty meals of potatoes, fried fish, tomatoes, and cucumbers with dill, and a chatty woman named Faina kept me occupied.

Indeed, one of the most interesting parts of the train trip was the glimpse it gave me into the lives of ordinary Russians. It was like a good, long dose of reality TV – perestroika style. I shared my compartment – the size of a not-so-big walk-in closet – with a British woman, a Russian student, and a 70-year-old Russian man who didn’t speak English but had a grocery bag of food that mysteriously did not deplete as he ate during the journey. Hard-boiled eggs, bread, tomatoes, and beer were the endless items in the magical bag. His smoking, done in the gap between the train cars, became more frequent as the journey continued. In preparation for arrival in Moscow, he plugged his electrical shaver into an outlet in the passageway of our train car and ran it over his chin.

The most social place on board was the dining car, where I met a red-faced, vodka-swigging university administrator from Omsk, a city near the Ural Mountains, and tourists from Holland, Slovakia, Slovenia, Spain, Britain, and Finland. At the beginning of the trip, the dining car offered standard Chinese fare – salt and pepper chicken and sweet and sour pork ($5-$10). On the second leg of the

journey, through Mongolia, the more Spartan train didn’t have a dining car at all, though we were provided with a complimentary vacuum pack of cheap, fatty salami and two pieces of bread to sustain ourselves for 36 hours. Fortunately, I had picked up a Philly cheesesteak at an American-style deli in Ulaanbaatar before getting on the train again. A dining car was attached once we crossed the border into Moscow, and borscht and caviar appeared on the menu.

But by far, the best sustenance came from the babushkas that huddled at the train platforms we rolled into selling traditional homemade Russian fare like pancakes with cottage cheese and roast chicken legs ($2).

The music, like the food, was also a source of amusement. It played on speakers in the compartments. Fortunately there was a volume switch, so when the music got to be unbearable, I could shut it off, thought my Russian compartment mates looked annoyed when I did this. American country music and Elvis hits were followed by Russian techno hour, when the speakers pulsated with dance beats. Somewhere in between, the train DJ put on the Platters’ “Only You” followed by Wham!’s “Careless Whisper.” At one point, the music was unidentifiable, sounding like a cross between techno and cabaret.

As we plodded steadily through thousands of miles of Russian countryside, which looked not unlike Canada’s Northwest Territories, I began to lose my sense of time. Train lag – yes, that’s the equivalent of jet lag – made me even more disoriented. I didn’t think train lag was possible. But after moving through four time zones in less than 24 hours, I found myself yearning for dinner at 4 p.m. and feeling drowsy even before the sun went down.

The cabins began to have a veritable funk by the second-to-last day of the journey. Some passengers were kind enough to splash on some cologne; others didn’t bother. People began to lose their energy – the Russian kids that ran down the halls earlier in the week stopped screaming and remained in their compartments. I was irritable, and slept less and less though I was tired.

Many passengers likened the experience to a cruise – for better or worse. “When you get on a plane, you don’t speak to anyone. But everyone was taking the vodka out, and it’s all very social. You make a holiday out of getting from one point to another,” said Sally Kift, from Leeds, England.

Finally, the birch trees of Siberia gave way to Stalinist architecture and gaudy Russian Orthodox churches with gold crosses and onion-shaped domes. We were within miles of Moscow, and I had survived the longest train journey in the world.

GETTING THERE

United Airlines flies to Beijing from La Guardia via Washington, D.C., and Chicago. Travelocity.com has roundtrip fares from $2,121. Northwest Airlines f lies to Beijing from La Guardia via Minneapolis and Tokyo. Travelocity.com has round-trip fares from $3,009. Charges and taxes are not included. Fares subject to change.