The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Mysterious 500-year-old tapestries depict a unicorn hunt.

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

This graceful little figure is a one-of-a-kind version of the cherished character.

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

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

A crumbling hospital from the 1850s on Roosevelt Island.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

Famously misunderstood wonder of the ancient world

The world's largest collection of witchcraft regalia.

The sign at the garden gate reads: "These Plants Can Kill."

This tangled English forest looks like something right out of a fairytale.

A much-maligned monument to teetotalism.

Home to a vast and influential collection of Shakespeareana.

Look closely and you’ll notice that the color changes a third of the way up the tower.

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

There’s a hidden military meme engraved on the World War II Memorial.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A faded reminder of what was once a common sight in London during the Blitz.

On the eve of a condemned prisoner's death, this bell rang 12 times outside their cell.

The ritual has been performed uninterrupted for nearly 700 years.

A museum marks and documents the site of the Titanic's launch.

Home to the Titanic Historical Society's collection.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.