SOMEWHERE IN WILL COUNTY, Ill. – Off a busy suburban road, a locked gate hides seven hallowed acres where men ride Lilliputian trains.

Here, somewhere in Chicago’s southern suburbs, a group of men have built the Chicago area’s last haven for a breed of train enthusiast captivated by models just big enough for an adult to ride.

“You’d never know it was there driving by,” said Lockport resident Bill Molony, president of a regional railroad buff society, who has been invited behind the gates.

Illinois Live Steamers got its start almost 40 years ago when four dozen model train enthusiasts paid about $30,000 for an orchard in Will County, founding fathers say.

Today, the group has about 100 members, and that apple and pear orchard has become an exclusive and expansive model train layout where the secretive hobbyists can practice machinists’ skills, run their trains and share a love of the rails.

The train viewing guest list is invitation-only.

But after months of calls, ILS agreed to allow some Daily Southtown staffers inside the compound on one condition: The club’s secret location could not be revealed.

“It’s private; it’s not open to the public,” explained ILS president Rick Tracy, who said he once turned down a request from Playboy magazine to do a photo shoot there.

“It’s not an amusement park. This is a high-tech hobby,” he added.

Tracy and others say stealth is needed in order to keep outsiders from discovering and vandalizing their clubhouse and expensive property.

“Everybody seems to know where we’re at out here,” said Russ Decho, 80, a Westchester resident and founding member.

People have turned up at the gates and asked to ride the trains, but they are turned away, he said, adding, “It is private property.”

Neighbors are certainly aware.

“Oh, the train guys!” says Eileen Batasich, who lives down the street, when asked about the club.

“I used to take my boys over there to take rides,” she added.

The small trains chug with a realistic clackity-clack over the tracks, rolling under trees, over bridges and through a tunnel.

They travel past working water towers set up for the steam-powered engines (with signs warning not to drink from the hose), small model houses and a life-size depot with a flashing electric crossing sign.

“It’s not just a toy train running around a Christmas tree,” says member Jack Bath.

Nearby, Ralph Tucker, 65, a retiree from Elk Grove Village, stood next to his train and drank from a bottle of Gatorade after a morning’s labor.

ILS members are expected to do plenty of work to keep the place running.

Members like Ray Pieper, 83, who retired as Orland Park village attorney about 16 years ago, enjoys the work and say it keeps them fit.

“If I didn’t have classical music and the live steam hobby, I probably would have gone berserk years ago,” said Pieper, who runs a 40-year-old Mogul steam train.

“It was a great relief from the tensions of everyday life,” he added.

Operating a miniature steam train isn’t easy.

“You’ve got to watch the track, your fire, your water – you have to make sure you’re lubricating the cylinders right,” Pieper said.

“It’s more fun than pulling a toggle switch and the thing takes off,” he added.

Today, most of the trains used at the club are battery-powered and modeled to look like modern diesel trains – a trend lamented by some steam purists.

Hobbyists say some of the trains derail on occasion, but they move so slowly – about 3 mph – there’s not much of a chance anyone will be hurt.