A winding path built in secret on the edge of the continent.

A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

An artsy hidden staircase leads to breathtaking views of San Francisco.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

Named the fifth most beautiful building in America in 1885, this former courthouse boasts the best view in the Village.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

The oldest surviving synagogue in New York City is now a soaring art space.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

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

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

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

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

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Tucked in the back of this amazing antique store is an important piece of medical history.

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

Visit the monolithic tomb of America's most famous general.

A terrific purveyor of natural history objects and curios.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

World's first "penitentiary," meant to be humane, drove men insane.

Rising out of a clearing in New Jersey's Pine Barrens is an Aztec-inspired monument to the "Lindbergh of Mexico."