Storage warehouse of the rich and famous.

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

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

During the holidays, a vintage subway train whisks New Yorkers back in time.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

A home built with marble tombstones from the graves of 2,200 Union soldiers buried in a Virginia cemetery.

The factory that helped produce a dominant form of lighting before Thomas Edison.

A historic covered bridge, only one of two remaining in North Carolina.

Trace the history of writing at this unusual North Carolina destination.

The first statue of Christ sleeping on a bench in the United States confused its affluent parish.

These strange large stones served as a campsite and lookout post for generations of Native Americans.

Conjoined twins Daisy and Violet Hilton were stars of the vaudeville circuit.

This scented city oasis was a labor of love.

This nine-story building can be played like an instrument.

An accidentally hidden library containing the ephemeral history of New York.

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

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

There’s a secret bunker inside the Brooklyn Bridge, but the city won’t say where.

This Manhattan skyscraper is a reminder of the brief but glorious age of urban air taxis.

A very classy 1920s-era bar right in Grand Central Station.

Elevated freight railway turned wildly successful urban park.

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

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.