This weekend, Chicagoans get the chance to tour some of the most historic buildings in the city as part of Open House Chicago.

That includes one very fortified building that sits at the heart of the nation’s financial system.

You may have first heard the name Austan Goolsbee when he was serving as a top economic advisor in the cabinet of former President Barack Obama.

Now, he’s president of the Federal Reserve Bank of Chicago — one of 12 regional federal reserve banks that make up the nation’s central banking system.

Goolsbee is also one of the voices on the Fed’s Open Market Committee that decides what to do with interest rates, specifically the federal funds rate.

“We do basically three things at the reserve banks,” Goolsbee said. “I go to the FOMC meetings where we vote on interest rates. Second, we’re the supervisor and regulator of a lot of banks in the district. Third, the Fed is the bank to the banks.”

This weekend, visitors can learn all about the Federal Reserve and get a rare glimpse at an historic and heavily fortified building more than 100 years old.

They won’t get to see any vaults of cash — just an ornate lobby with 12 columns representing the 12 branches of the Federal Reserve. (By the way, those vaults of cash are holding billions of cold, hard dollar bills at any given moment.)

“We run $200 million of cash in and out of here every day,” Goolsbee said. “If you go to your ATM and take out cash, chances are it was sitting in our vault at some point.”

Goolsbee says the goal of the weekend event is to give the public a glimpse into what can be seen as a very secretive organization.

“It’s important as part of the Fed system that people see it’s not a crazy conspiracy,” he said. “People are here trying to keep the financial system safe.”

The best way to get educated is in the Money Museum, which is ironically free to the public.

Visitors can gawk at a giant cube holding $1 million in cash and learn everything they might not have known about what’s in their wallet.

For instance, there’s a great chance your dollar bill sat in this very building before entering the world. On the left side of every $1 bill is a letter that indicates which Fed bank it came from. “G” means Chicago.”

And while we have a top economic official like Goolsbee, we should probably ask him what’s going to happen to those interest rates, and whether the fed can bring down inflation without causing a recession.

“There’s never been a central bank that has been able to bring inflation down this much without having a big recession,” he said. “For some reason, I think right now we might be able to pull it off. It’s not a guarantee — we’ll have some bumps in the road we’ll have to navigate.”

Speaking of driving inflation down, one function of the Chicago Fed is to take old or worn dollar bills out of circulation.

How do they do that? By shredding them and giving them away as something akin to a party favor.

The annual Open House Chicago runs Oct. 14-15 and also includes sites like Walt Disney’s birthplace, the Pullman National Historic Park and more. Admission is free. For more information, visit openhousechicago.org.