A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

A European-style bath house in Chicago.

This shop for all your super spy needs hides an educational secret.

The faint remains of a Polish news empire still linger.

Theater has had many different incarnations but has survived the ravages of time.

Where old school Polish Chicago and young hipster Chicago live side by side.

Combination beer garden and music venue in the heart of Wicker Park.

Internationally known record store and purveyor of "dusties."

Odd, decrepit fountain honors Chicago author who had mixed feelings about his hometown.

G.V. Black, the Father of Modern Dentistry, keeps an eternal eye on Chicagoan’s teeth from his perch in Lincoln Park.

All of Chicago's wood-paved streets are long gone but two alleys remain.

No one knows how many bodies are in this vault in a Chicago public park.

Beloved bar home to musicians of all eras and reputations.

Parking lot where a Chicago mayor was inaugurated under very sketchy circumstances.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

A speakeasy takes on Chicago's drinking culture.

Once at the center of U.S. finance, the historic Trading Room was meticulously recreated piece by piece and rebuilt in the Art Institute.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

The unique collection often goes unnoticed by visitors focused only on the archaeological objects.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

Once home to an aristocratic family and a workers' organization, this intricately tiled building now houses a chain restaurant.

66,000 pieces of art, donated by one of the world's richest men.

Part bookstore, part café, and part forest.

This ancient jade mask depicting the Zapotec bat god was found in the ruins of the pyramids of Monte Alban.