Stockholm's deepest subway station is also a stunning ecological wonder.

The library's graceful rotunda is like a bibliophile's temple.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

One of the few Glatt kosher delis in the United States is a cornerstone of its Hasidic neighborhood.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

Outstanding taxidermy dioramas showcase the grandeur of the continent's wildlife with spooky realism.

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

A famous songsmith's custom piano, dubbed "High Society," is hidden just out of sight in one of New York's finest hotels.

Beautiful mosaics cover the first stations opened on New York City's newest subway line.

One of only two remaining Victorian-era greenhouses in New York.

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

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

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

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Slyly buy a shake in the Parker Meridien lobby.

Peek through the gates at this oasis from the city, full of Old English charm.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

Ride the subways of yesteryear.

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

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

New York City's smallest piece of private property.

A miniature rainforest is growing inside of a Midtown Manhattan office building.