The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The last masonry skyscraper ever built reveals a transitional moment in architectural history.

This national park dedicated to the tallgrass prairie ecosystem still displays its military past.

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

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

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

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

A historic and oft-filmed prison stands in a Chicago suburb.

This modest post office sits on the site of H.H. Holmes' famous murder castle.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

An enormous park-like oasis, full of famous Chicagoans' graves.

One of Chicago's last seafood smokehouses perfects a dying breed of fishcraft.

Not to be confused with the iconic New York City skyscraper, this Chicago building is a vibrant hub for artists.

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

This urban drawbridge gained eternal pop culture fame when the Blues Brothers jumped it while it was raised.

This historic Illinois "Muffler Man" has been converted from axe-touting lumberjack to rocket-wielding space ace.

The bears may be gone, but their old cages can still be found.

The site of Paul Revere's historic two lantern warning.

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Visit the monolithic tomb of America's most famous general.

This tower-tomb honors a president who only held office for a little over a month but dedicated his life to his country.

The grave of America's 11th president is not in some grand monument but instead it's hidden away on the grounds of the Tennessee Capital.