On the right-hand side, we are right here at the base of the second tallest building in the city of Chicago.

People have been telling me for years that I need to go on the Chicago Architecture Boat Tour.

I wasn't opposed to it, but frankly, it just didn't sound like the sexiest attraction in town.

Well, I finally went on the tour last summer,

and let me tell you, I was wrong. The Chicago Architecture Boat Tour rocks.

The Chicago River runs through the city, so you can actually float, traffic-free, through its skyscrapers.

There's no top on the boat, so you just kind of lean back and look up.

It feels sort of like you're in a canyon.

On the tour, we saw the world's tallest skyscraper designed by a woman, caught a glimpse of an old

building with the relic of a blimp landing still attached to it, and floated past the fancy

gym where Barack Obama and Oprah used to work out. But then, the tour guy pointed out something

less flashy. A compact, green, clapboard house nestled unassumingly at the base of the bridge.

The guide only briefly mentioned the house, basically just pointed out its existence and then moved on.

But something about that strange little house stuck with me.

And once I saw that first one, I started noticing them everywhere and wondering about their stories.

I'm Johanna Mayer, and this is Atlas Obscira, a celebration of the world's strange, incredible, and wondrous places.

Today, we visit the Chicago Bridge Houses, and we get a peek inside a world I never even knew

existed until I saw that little house.

The world of bridge operators.

After this.

Thank you. operators after this. Patrick McBriety is the first bridge historian I've ever met.

But he wasn't always into bridges.

...