The world's longest tunnel with an undersea section.

Japan's largest area of "pink moss" turns the hillside bright pink every spring.

A gorgeous, nostalgic café housed in a lofty old warehouse, lit only by petroleum lamps.

This abandoned railroad got a new life as a scenic promenade cutting through the city of Otaru.

Tucked away inside this concrete building is a church and its grand display of brutalist architecture.

The name of this tiny pocket park tucked between two buildings on Manhattan's Upper West Side is Latin for its location: "seventy-one."

This diesel train serviced the Brooklyn waterfront for more than three decades.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

A quiet and contemplative oasis in the middle of New York's bustle and riot.

Hidden behind a gate in Greenwich Village is a little farmhouse that once served as the writing studio of a bestselling author.

A celebration of capitalism in Midtown.

Rusting away on the edge of New Jersey are the remains of a Cold War missile launch site.

A former seaside jewel built for the everyman is now simply a neglected art deco fortress.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

The home of aviation trailblazers, in a remote corner of the big city.

This outpost of America's most popular fast-food restaurant is housed inside a palatial mansion.

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

Beautiful mosaics cover the first stations opened on New York City's newest subway line.

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

The "Seinfeld" diner.

The studio of influential composer Charles Ives is perfectly reconstructed, hidden in the back of the American Academy of Arts and Letters.

The site of a tragic massacre that spawned a multimedia franchise.

Nine nice parcels of land along a flight path offer a quiet respite... until a plane soars overhead.

A remnant from the golden age of aviation still in use today, Pan Am's Clipper service took off from this Art Deco gem.