The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

North Carolina's only restored fort from the French and Indian War.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

This vast kitty-themed collection illustrates the history of human-cat interaction.

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

This haunting tombstone comes complete with a heartbreaking story of love and loss.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

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

The 28-foot granite map plots the locations of 40 theaters in New York City.

One of the most enjoyable bits of history at Coney Island and “the most romantic ride in the world.”

This outdoor gallery of graffiti-covered walls pays homage to the past, present, and possible future of street art.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

Hundreds of antique bank vault locks on display in New York City.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

This museum dedicated to an oft-overlooked support industry features a surprisingly moving brass diorama of a man being saved from a sinking car.

Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

This historic train station has been converted to a locomotive themed hotel.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Dinosaurs invade a suburban Nashville neighborhood.

This replica of the Greek structure is in the heart of Nashville.

Andy Griffith's hometown has made itself up to look like the fictional town of Mayberry.

This colonial cabin is the oldest building in High Point, built by one of the first settlers in the area.