Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

This collection of neon icons is preserving Arizona's history, one sign at a time.

The awe-inspiring ship from the golden era of cruising has an incomparable history and a reputation as one of the world’s most haunted places.

The world's largest indoor go-kart racetrack is hiding in Connecticut.

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

The world's largest collection of fine-scale miniatures and one the nation's largest collections of antique toys.

There are more than 4 million bricks inside this unofficial Lego museum in a former middle school.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

First planned industrial community in the United States.

The residents of the Neighborhood of Make-Believe live without much fanfare within the Pittsburgh Children's Museum.

When it opened during the final years of the embargo, all the drinks and cigars were free.

This tiny, painted door at the base of a tree stump has been a fixture of the Harvard University campus for decades.

A monument celebrating the idea of reaching inaccessible places.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

A psychedelic labyrinth on the San Francisco bay.

Home to Hollywood history and a very special salt crystal.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

Recognized the world over as the home of the McCallisters in the 1990 movie "Home Alone."

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

A priceless collection of the Nation's cryptologic history.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

The land is home to swimming ponies and a legendary 18th-century treasure.