The only Leonardo Da Vinci painting in the Western Hemisphere.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

A faded sign from the 1920s remembers Baltimore's resistance toward banning alcohol.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

Public opinion is still divided on this enormous sculpture in front of Baltimore's Penn Station.

This elaborate towering structure was once famed for its revolutionary height.

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

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

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

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

This sprawling mini-golf empire is an impressive testament to a disappearing attraction.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

This cathedral dedicated to Louis IX, sainted King of France, holds many secrets.

These 11,000-year-old mounds may be the oldest known human-made structures in the Americas.

Chicago's largest cemetery is full of beautiful Victorian monuments and more than a few ghost stories.

An antiquated German apothecary on Chicago's North Side.

A Bibliophile's Dream.

The beloved home to all publications indie, erotic, and punky.

A hidden oasis just north of Chicago's Chinatown.

In 2004, a Dave Matthews Band tour bus dumped 800 pounds of waste off a bridge and onto an unsuspecting tour boat below.

The last remaining vestige of a popular 1999 public art display.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.