My 10-year-old son stood for a minute on the threshold of Brickmania Toyworks as if it were Disneyland and he were trying to choose a ride. Then he darted to a cluster of Lego buildings covering a big table.

“Mom! Mom, it’s an actual model of St. Paul, with tanks in the street!” he chattered with excitement. “Please! We have to get these tanks! And there’s Landmark Center.”

Sure enough, there stood a model of Landmark Center done in tan bricks with green cone turrets. In front of it was Rice Park, complete with trees and a fountain made of Lego bricks and overrun with tanks made of gray pieces.

That’s the beauty of Lego displays. You’re not limited by reality. Want to put “Star Wars” characters around a boardroom table in a miniature office building? Go for it. Feel like putting Godzilla in the Tokyo harbor? Tanks in Rice Park? Why not?

Like many boys, my son is into Legos. He builds off-the-shelf sets and then takes them apart and constructs his own creations. Apparently, some adults do this, too, with amazing results.

“We love the brick,” explained John Gerlach of St. Louis Park, who was volunteering on the Saturday I took my son and a couple of friends to the monthly open house at Brickmania Toyworks. The warehouse in Northeast Minneapolis is home to two local Lego clubs.

The newer Twin Cities Lego Train Club is composed of John and Ross Neal, a father-son team behind the realistic re-creation of downtown St. Paul.

Gerlach is a member of the Greater Midwest Lego Train Club, which was started in the 1980s by a local group of adult fans of Lego (known as AFOL in the online communities, where they swap tips and inspiration). The older club’s constantly evolving layout sprawls over several tables and has a charmingly jumbled feel.

” ‘Plan’ is too strong a word,” Gerlach said. “We just start building, and if something doesnt work, hey, its Lego. We just pull it apart.”

CREATIVE OUTLET

Electric trains loop past a snow-capped mountain sporting a white sign that says “Mt. Annika,” named after a club member’s daughter. Look closely and you’ll see a polar bear on the slope with a mountain climber in its mouth.

Nearby, a soccer game was in progress with mini figurines in uniform watched by mini spectators sitting in bleachers. There’s a train station with tall arched windows, a clock tower, a steep roof and a platform crowded with mini commuters.

There are streets lined with buildings, sporting intricate architectural details, clear Lego windows, railings and details like striped awnings and ivy crawling up a wall.

There are cars, school buses, an ambulance and fire trucks. And, yes, there is a bridge crossing Tokyo harbor and Godzilla wading through blue Lego pieces, ripples in his wake.

“I tell people I’m creative but not artistic,” said Gerlach, one of many people who has contributed over the years to the layout. “I can’t paint. I can’t draw. I can’t sculpt. But with Lego as a medium, I can be creative.”

The open houses draw several hundred people, and on the day we visited, families with kids wandered the perimeter. A boy about my son’s age spotted Homer Simpson and excitedly pointed it out to his dad.

“We love the point and screech,” Gerlach said.

“Some clubs put up ropes or plexiglass, but we don’t. We want kids to be able to get close. The club also has an unwritten rule: If any kid brings their Lego train, the club runs it on the track,” he said.

For the enjoyment of the shortest and youngest Lego fans, clear brick windows look into a subway system running below street level.

Several empty tables in the middle of the room are stocked with bins of Lego bricks where kids were building cars and racing them down a wood ramp. That’s where my friend’s preschool-age son ended up as his mom and I looked at smaller dioramas along the walls. We saw a re-creation of Germany in April 1945, with a bombed-out gray brick building, tanks and piles of Lego rubble.

We saw the Bates Hotel from the movie “Psycho.” But the diorama that stopped us in our tracks was a detailed re-creation of a Vietnam War battle scene, complete with armed mini figurines crawling out of a tunnel into a rice field. A monkey sat on the upswept black roof of a pagoda and blades twirled on a military helicopter.

“I guess it’s an art form,” my friend finally said.

NICHE MARKET

The Vietnam diorama is the work of Daniel Siskind of Minneapolis, the founder and owner of Brickmania, a business that sells custom Lego kits, most of them military related. He donates the warehouse space for the two local clubs.

Siskind fell into the niche market of custom Lego builds a dozen years ago, after he made a blacksmith shop out of Lego bricks and put it on eBay as a lark. He sold 10 duplicates within the week.

“I didn’t think there was that kind of demand,” he said. “Then I posted a picture of a tank I’d built for myself, and I was flooded with emails from people who wanted one.”

Siskind aims for historic accuracy and studies technical manuals to get details right, down to the swiveling turret on a $165 Panzer IV Ausf E German tank. He employees five people and ships kits internationally.

Brickmania sells kits during the open house, but they are on shelves off to one side, and the warehouse doesn’t feel like a store. My son did end up buying a few small weapons that are compatible with Lego mini figurines — a rapier and some photon pistons — made by another small business called Brickarms, based outside Seattle.

“This is so cool,” my son said, as he surveyed the scene one last time. “I didn’t know there was even something like this.”

I had always assumed that someday I’d sell my son’s Lego pieces at a garage sale or pack them away for grandchildren. Now I wonder if my boy is just at the start of a lifelong hobby.

THE SCOOP

What: Brickmania Toyworks

Where: 1620 Central Ave. N.E., Suite 177, Minneapolis (enter on18th Avenue Northeast)

Information: 612-545-5263, brickmania.com

Hours: 10 a.m. to 4 p.m. every second Saturday of the month

Cost: Free

Target audience: Train buffs and toy brick fans

Crowd pleaser: Mini landscapes made entirely of Lego bricks

Avoid: The Lego store at Mall of America. Brickmania is cooler.

Tip: Bring a book if your kids are more into Legos than you are. You’ll be there for a while.