This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

This innocent-looking townhome is actually a subway exit.

The Underground Railroad passed right through this historic Brooklyn Heights church.

Abandoned 19th century homes once occupied by naval officers, soon to be demolished.

This impressive mansion in Vinegar Hill has some mysterious details in its architecture.

Walk into the 19th century without leaving Brooklyn.

Storage warehouse of the rich and famous.

The one-time office of the architectural firm that ushered in the Gilded Age is now a Club Monaco.

Where there’s manufacturing, there’s fire!

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

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

Nope, not Washington Irving's house.

The smallest island in Manhattan is a manmade landfill dominated by a Buddhist peace arch.

The former sign of this immortal music venue is just that--undying.

One of the few remaining American elm trees in New York’s Tompkins Square Park was the birthplace of a new religion.

Cheap pizza and all of your naughty bedroom needs housed in a stunning example of Art Nouveau architecture.

The competition: breathe deeply as long as you can.

The iconic Manhattan corner that was once the site of the Beastie Boys' fake clothing store.

This Fifth Avenue church has long been the favored worshiping place of Broadway actors and vaudeville performers.

There must be a pun in this haystack somewhere...

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

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

Once considered the height of medical modernity, this structure is now the oldest remaining component of Roosevelt Hospital.

Possible relics of the ancient Roman city are hidden in this restaurant's façade.