The rogue roots are gradually consuming some of the historic marble grave markers.

The U.S. Fish Commission’s effort to mass produce carp.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

A simple stone remembers one of the most menacing horses in the Swedish military.

Don't be fooled by this fake medieval facade even if it is almost 300 years old.

This lone tree and dramatic sandstone outcropping are so beloved by Michiganders they can be found on one of the state’s coins.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

Paris' linguistic guide to the international language of, yes, love.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

A steel paper plane is all that remains of a crashed aircraft that caused an amazingly small amount of damage.

The center of the only hemisphere that awards visitors with a commemorative coin.

This bronze sculpture on a former squash court marks the secret origins of the Atomic Age.

The final resting place of up to 6,000 Confederate soldiers, the largest mass grave in the Western Hemisphere.

It was originally part of a "terrible lizards" collection at the 1964 New York World’s Fair.

The final resting place of the world's first nuclear reactor.

One of the largest aviation events in the world brings half a million aircraft enthusiasts to Wisconsin each year.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

Opulent downtown movie theater now houses cars as an indoor parking garage.

Detroit’s downtown castle is one of the oldest structures in the city.