Amid skyscrapers and traffic exists this unique aquatic ecosystem.

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

A mysterious, abandoned building rotting on the Brooklyn waterfront.

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

The gilded vestiges of a sterling department store can still be found in a Brooklyn shopping center.

The rare American Civil War-era weapon was never fired in anger.

A working monastery hidden away in Brooklyn once abutted the location of a former inebriate's home.

On the hills of Bay Ridge stands a house straight out of a fairy tale.

An abandoned subway tunnel that could have reinvigorated Staten Island still lies somewhere beneath this Brooklyn park.

Brooklyn's Barkaloo Cemetery is the resting place of a scant two bodies.

The remains of a 19th century spring, and the site of an infamous unsolved murder.

A bronze plaque at an intersection in Hoboken marks the place where the game of baseball first took shape.

The boulder on which Alexander Hamilton laid his head after a deadly duel can still be visited on the New Jersey coast.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

Seven golden statues rise into the sky from sculptor Victor Victori's New Jersey front lawn.

Originally built in 1869, this castle is currently part of Felician University's campus.

A field of nothing but boulders which resembles a giant's gravel driveway.

These hooded graves are the only of their kind in the United States.

The oldest remaining authentic Putt-Putt course that Donald Clayton created in Ohio.

How did a 2,000-year-old Roman column find its way to a Chicago park?

The last remnants of a lakeside airport that was bulldozed overnight by the mayor of Chicago.

These abandoned grain silos and tunnels are an urban exploration dream.

This cheerfully-named branch of the Chicago River is the fetid result of years of blood, entrails, and meatpacking waste.

A Japanese temple, old German townhouses, and public chess tables offer a peaceful escape from the bustle of the North Side.