A hidden alley in urban Baltimore is a haven for graffiti artists.

New York City's smallest piece of private property.

A layered tribute to the work of mosaicist Isaiah Zagar.

Final resting place of two dozen New York City harbor ships.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

Failed state-supported institution meant to rehabilitate students with intellectual disabilities.

Eccentric stone cairns built on a public New York City beach.

One-time largest man-made structure in the world will be a park in 30 years.

A town trapped in time - 1958 to be exact.

One of the most enjoyable bits of history at Coney Island and “the most romantic ride in the world.”

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

Try not to get slimed in Tribeca.

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

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

This anonymous businessman sculpted in bronze became an enduring memorial after 9/11, and had been mistaken by rescue workers for a survivor in the rubble.

Where now stands a 42-story condominium tower of marble, glass and steel was once the central market of New York’s slave trade.

Unrepaired walls from a 1920 anarchist bomb attack.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

Lie in a hammock where George Washington stood.

A Red Hook dive bar that is holding onto its roots.

Once America's longest-manned military fort, now an abandoned hulk.

One of only two commuter aerial tramways in the United States.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.