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

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

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

This memorial honors thousands of enslaved Africans and their descendants who died in colonial New York.

A Saint Nicholas-themed ghost town in the Mojave desert.

One of the largest, oldest, darkest, quietest motel rooms in the world.

See massive fossils that are over 200 million years old in northeastern Arizona.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Rippling sand dunes frozen in the Arizona rock.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

These banned cigarette vending machines now sell little pieces of pocket-sized art.

An overlooked memorial honoring the local Washington residents who died in World War I.

Washington's iconic carousel has a nice piece of Civil Rights history.

The most accurate timepiece in the world.

The national park was once a plantation estate.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

A super-sized promotional trick that is now a D.C. landmark.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A historic neighborhood church is reborn as a psychedelic arts collective.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.