A hidden "place of interment for gentlemen."

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

This humble historic facade hides a history of boozing and the gentlemanly sport of rat-fighting.

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

The iconic Chicago sculpture hides a beautiful and easily overlooked plaque on the backside.

A strange rock in Chicago marks the spot where a tree once stood in honor of the 18th President.

A goddess-topped water fountain in Chicago was created thanks to the dreams of a thirsty newsboy.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

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

A display of magnificent stained glass windows is the first exhibit of its kind.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

A hollow cement depiction of time's inexorable effect on the human body.

A Bibliophile's Dream.

The subtle science of a master molecular gastronomist.

An acoustic anomaly with a mysterious cause.

An accidentally hidden library containing the ephemeral history of New York.

An unassuming secret door once led to a legendary watering hole.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

Plot your trip through the city on the sidewalk.

Red frames showcase remnants of one of New York's original subway stations.

The last remnants of what was once one of the world's grandest hotels can now be found in a Manhattan subway station.