The oldest U.S. Government building in California, and it's State Historic Landmark #1.

The rusting remains of the largest assembled WWII fleet on the West Coast.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.

After serving in World War II and picking up Apollo astronauts, this aircraft carrier has been turned into a museum overlooking the San Francisco Bay.

An enormous artwork that colorfully celebrates over 150 years of US military achievements.

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

Tiny memorials honor individual victims of the Holocaust.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

This saltwater swimming pool, which is the last of its kind in the United States, is slowly crumbling within sight of multiple high-end beachside hotels.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

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

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

A large portion of this navigable canal runs under Paris's famed boulevards.

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

The location of this small park was once the site of an infamous public morgue.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

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

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

A concrete mushroom that divided Stockholm residents for nearly a century.

It houses the remains of a 17th-century version of the Titanic.

A World War II evacuation tunnel turned into a history display of Croatian state and people.