PITTSBURGH (KDKA) – It is part science, part history, but pure Pittsburgh.

That is why children of all ages have flocked to see the Miniature Railroad and Village at the Carnegie Science Center since its arrival on the North Shore in 1992. Before that, it was on display on the second floor of the Buhl Planetarium after it was donated by the original owner in the early 1950s.

Now, a big part of Pittsburgh’s history is being added to the display.

Today, that marquee draw at the Science Center reaches a milestone birthday. For its 100th birthday, the miniature railroad has evolved.

There have been countless new editions to the display, including the Westinghouse Atom Smasher back in 2017 and a model of the original Primanti Brothers display more recently.

Allegheny County Executive Rich Fitzgerald was at the Science Center as they unveiled the new addition for the 100th birthday.

“New Pittsburghers who are coming here to really understand about our heritage when you talk about from the late 1800s to the middle of the 1900s and 20th century, and all the history showing how our stores were, how our sporting events were, how our industry was,” he says.

Kim Amey, the interim Deputy Director of the Carnegie Science Center made the announcement about the addition: “I am very pleased to announced the iconic downtown retail mecca Kaufmann’s Department Store is this year’s edition.”

WATCH: KDKA’s Rick Dayton reports live from the Carnegie Science Center

Even in miniature form, the new Kaufmann’s is massive. It features 15 display windows, a massive crystal chandelier and the original street level Kaufmann’s clock.

Modelers wanted to include the legendary retailer for years, but the current building in downtown Pittsburgh would not have matched the scale of the rest of the miniature railroad and village.

Until now.

“Our research brought us to the original Grand Depot retail building — to the original version of the building that was there on Fifth and Smithfield,” says Patty Everly, the Curator of Historic Exhibits at the Carnegie Science Center. “That opened the door. That allowed us to add Kaufmann’s to the display.”

Kaufmann’s joins a display that contains more than a hundred local staples — places like the original Primanti Brothers, an amusement park, even miniature Pirates playing baseball at Forbes Field. Now Kaufmann’s is part of the mix.

The model has been closed since September to make the changes and to add the Kaufmann’s replica. Historically, it opened in Pittsburgh in 1885. Science Center members got to see the renovated display today.

“You finish a model like Kaufmann’s and you are excited, and you show it to other Science Center staff, and then you get to show it to people though which our members are coming today. We open to the public tomorrow, the 21st. That just — it’s a sense of pride in what we do,” says Everly.