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

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.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

New York City's smallest piece of private property.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

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

A dilapidated dock tells the story of Titanic's missed arrival.

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

Elevated freight railway turned wildly successful urban park.

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

Tourists who rely on a transit map to find the iconic Beatles location often end up in a far-off neighborhood.

Putting the "mod" in "modular" since 2000.

Sculptor Antony Gormley used chaos theory and fractal growth to design his tallest creation.

The unusual patterns in this rock formation result from two distinct modes of weathering.

A tunnel with windows, so you don't miss out on the impressive views.

Contains a wealth of information about the first exploration and later use of the Green and Colorado Rivers.

This Moab institution functions as both a rock store and a small natural history museum.

These tall, red sandstone pinnacles outside Moab are often forgotten amid their more famous neighbors.

Within the former ghost town of Cisco is a carefully restored tiny town with one resident and its own art residency.

This statue intended for children to enjoy became a minor political spat.

This impressive Boston holy house is the American mecca for Christian scientists.

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

Tragedy on Little Brewster Island memorialized.