This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

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

A popular European tradition makes its way to the states on one of America's most famous bridges.

Nondescript elevator doors open to reveal a stunning, surreal world.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

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

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

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

Read a book next to a Midtown waterfall.

A hip bar decorated with walls of golden skulls.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A miniature golf course crafted inside the world's largest simulated cave.

In the bowels of a 19th-century brewery lurks a fine-dining restaurant offering an array of themed feasts.

"Where the ducks walk on fish."

This picturesque stream was up until recently the site of a ten story mountain of slag and sewage.

Locals call this magical moss-covered walkway the "Emerald Path."

This secluded walking trail is a hidden gem of a Pittsburgh park.

The abandoned coal loading dock is a canvas for unsanctioned art.

Pennsylvania's highest point is spotted with boulders which were pushed to the surface by nothing but cold.

This stone tower marks a lookout point over the historic Washington Crossing, and maybe some buried treasure.

It would take 35 firetrucks to fill this enormous glacial pothole.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

A failed piece of Orientalism has become the proud symbol of a community.