A pocket of serenity in hectic Buenos Aires, complete with a peaceful courtyard and massive library.

A mysterious architectural gem in one of the most elegant areas of Buenos Aires.

Museum housed in underground tunnels that date back to Buenos Aires's earliest settlements.

A gateway to a mysterious network of underground tunnels.

A tiny slice shop hides down an unmarked hallway in a Las Vegas casino.

A luxurious doomsday bunker hidden beneath an unassuming Las Vegas home offers the best of subterranean suburbia.

Stuck in a bygone era, the oldest subterranean shopping street in Japan hides beneath the popular Asakusa district of Tokyo.

Haunted house kitsch meets Japanese folklore at this theme bar where patrons can “die” and have their own mock funeral.

Serving you alcohol with a side of insanity. Also, costumes!

“Historical” markers commemorating the sites of fictional events depicted in a popular jidaigeki novel series.

Rice balls symbolize fate and relationship at this adorable shrine, which was once dedicated to the Buddhist Devil.

This abandoned, spaceship-like building is home to a museum so unpopular that it has been put on hiatus for over two decades.

This public bathroom takes the form of a 19th-century lighthouse that once stood on the spot.

Disused for decades, this freight railway bridge is finally being renovated into a scenic promenade.

Composed of scrap metal, a pair of platform-length murals chronicle Japan’s history, from the Big Bang to the development of modern Tokyo.

A cursed torii gate still stands on the edge of Haneda Airport, decades after its shrine's relocation.

A sad reminder of the World War II bombing stands largely unnoticed on a street corner.

The train engine is tucked under an apartment building on a quiet Tokyo street.

This museum showcases the art of ancient sword-making.

Designed by a computer, this intricate network of fluorescent green pipes has taken over a subway station.

A few hidden stones are said to bring fortune and love.

Take a few seconds to look at this abandoned, art-filled station as you pass by on the subway to Ueno.

A 17th-century Shinto shrine that is home to statues of Mickey Mouse and Pikachu.

After being lost for decades, this striking mural depicting the atomic bomb covers the wall of a busy Tokyo metro station.