"That train is taking me to South Africa," says five-year-old Lainey Albert.

But the place the train is heading looks more like Middle America. Its streets are lined with a feed-and-grain store, a five-and-dime, a Chinese restaurant and a movie house showing "Gone With the Wind." The town and the countryside and the trains are all smaller than life -- but too big for anybody's rec room. They're part of the modeltrain exhibition at the B&O Railroad Museum in Baltimore.

Three tiny trains roar through tunnels, around curves and into stations. Kids sit on stadium-like benches watching the display and making up games to play with the trains. Guess which tunnel it's going through next. My train can beat your train. Are they going to crash?

They don't, and after about ten minutes the model demonstration, given every half-hour, is over. As the model trains grind to a halt, the kids run to the roundhouse, a railroad heaven where all good trains go when they die. Arranged on real tracks confronting the revolving platform on which the engines used to be transfered from one train to another, are steam engines, freight cars, cabooses and passenger cars -- many of which you can board.

Kids crowd aboard the tiny Bride's Coach, a Cinderella-like car that carried Canada's governor-general and his bride home from their wedding in 1838. Legend says that any young woman who can sit perfectly still in the car for ten minutes will be married within the year. Some little girls make a valiant effort, but after roughly half a minute they give up and clamber aboard a platform where they can peer into what the museum calls "the secret train."

"Look, people are in there, pretend people!" says one kid. One of the pretend people is President-elect Lincoln, who rode into Washington unannounced in 1861. To indicate that Lincoln had made the journey without incident, a railroad official telegraphed cryptically to his superiors: "Your package has arrived safely."

Real packages, of course, went on mail cars -- until last year when the U.S. Postal Service stopped using the trains. In a railway post-office car, a relic of the recent past, kids look through Plexiglass at a pretend postmaster pigeonholing letters while the train ate up the miles.

"Like if you sent a letter to your grandmother it would go by train," surmises one kid who's only a little bit behind the times.

The kids' favorite is a little red caboose, vintage 1907. A pretend man, "just like the man in 'Roots' who worked on a caboose," is sitting on a bunk. While the pretend man rests, the kids take over his job. They climb up a ladder and perch inside the box-like cupola on top, watching for trouble on the tracks ahead. They don't see any trouble, but they do see some other trains they want to explore.

Most of the trains are originals, but some are replicas. Among the most famous replicas is one of the Tom Thumb, the first train to depart from Mount Clare Station, now the site of the museum. An eccentric New York millionaire named Peter Cooper fashioned the train out of an old boiler and some bicycle parts in 1830 because European manufacturers were reluctant to make trains for rough American tracks.

In addition to the full-scale replica, there's mini-demonstration of the Tom Thumb's first trip -- a race with a horse-drawn carriage. The kids push the button to start the race and the horse and the train forge ahead. They're neck-and-neck at first, then the train pulls ahead. The demonstration doesn't show what happened next, however: The train broke down, and while Cooper fixed it, the horse won the race. THE FARE AND THE FACTS

The B&O Railroad Museum is open Wednesday through Sunday, 10 to 4. Admission is $1.50 for adults, 75 cents for children under 12.

Take the Baltimore-Washington Parkway to Baltimore, where it will put you on South Paca Street. Turn left on Lombard Street and go to Poppleton Strteet, then left on Poppleton one block to the museum, which is at Pratt and Poppleton Streets.