Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

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.

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

A very classy 1920s-era bar right in Grand Central Station.

The "Seinfeld" diner.

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

Collapsing castle on the Hudson river was once the storage site of military surplus business.

This peaceful Massachusetts graveyard was one of the first "garden-style" cemeteries in America.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

Millions of numbers carved in glass represent the tattoos forced upon victims.

The site where Charles Dickens gave his first public reading of "A Christmas Carol" in the US.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

This landmark cemetery in Boston was created more than 300 years ago.

Two thousand artifacts from around the world collected by one woman who loved to travel.

A former seaside jewel built for the everyman is now simply a neglected art deco fortress.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

The flagship building of an early national restaurant chain is a superb example of terra cotta art.

Once home to the country's most gargantuan ships, this graving dock now waits for people to buy furniture.

New York's southernmost subway station is whimsically wavy.

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

This enormous banquet-themed artwork honors over 1,000 notable women throughout history.

New York's oldest concrete structure is being preserved thanks to the gentrification of Whole Foods.

Michael Jackson got Bad and Crocodile Dundee walked on heads in this iconic Brooklyn subway station.