Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This incredible second-century sculpture depicts a trio of gods worshipped by the ancient Romans.

Love, knishes, and best wishes from this legendary Lower East Side bakery.

A restaurant on Staten Island showcases a different grandmother’s cooking every night.

Vast network of air raid tunnels beneath Lombardy's capital.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

A monument dedicated to the civil uprisings that took place during the Pots and Pans Revolution.

Learn about Iceland's hidden folk at this school dedicated to the study of elves.

Established in the '60s, a family-owned tropical drink bar founded by Ray Buhen, bartender to the stars.

Giant Redwood-themed cafeteria operates under the golden rule, "Dine Free Unless Delighted."

A Byzantine-style concrete artwork pays tribute to a 17th-century saint.

An unprepossessing stone marks the last resting place of one of the most accomplished Native Americans in history.

This landmark jazz venue is the oldest continuously running African-American club in the United States.

This unique crypt designed by Frank Lloyd Wright for his longtime friend was not completed in either man's lifetime.

A celebration of one of the West End’s most recognizable figures, who made helping others his life's work.

Multiple monuments to a grizzled old mutt that survived the landscape of Butte's treacherous Berkeley Pit.

Modeled after a famous church in Vienna, Austria—but in Helena, Montana.