Cleveland's giant "free" stamp is a nod to the Civil War, but was misinterpreted for years.

It may be a "Smoke Free Ontario" today, but at this museum you can still get a whiff of yesterday’s Golden Age of tobacco farming.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Yo, Adrian!

Mural made of 100,000 pieces of hand blown glass, and one of the largest glass murals in the US.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A daily replay of the experiment that proved the rotation of the Earth.

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

Huge masonic hall in Philadelphia with lavishly themed rooms.

This small New York museum celebrates the mountainous artwork of a Russian mystic.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

A bit of retro transportation flair preserved in the world's largest department store.

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

The "Seinfeld" diner.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

Once the tallest building in the world and the site of “the highest dinner ever held in New York” this building now holds the most expensive penthouse in the city.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

After a water tower painting was accused of being an ad, a simple fix was made that gave the city a motto.

The Kalamazoo factory has 100 years of instrument-making, and one big wartime secret.

The spaceship-like theater, which is still in use, was one of the most popular exhibits at the 1964 New York World's Fair.