Walk through the history of American pop culture.

The trials and tribulations of marking Poe's grave.

George Washington's dentures and Queen Victoria's dental instruments are in the nation’s official museum of the dental profession.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

Ruins of an old sugar mill sitting quietly next to a park in rural Florida.

In Florida, these naughty monkeys live on their own mini-monkey Alcatraz.

Meet manatees face-to-face at this zoo for native species.

A vast array of tropical plants collected by a vacationing couple.

The highway's southernmost spot is a beloved local attraction.

A monument celebrating the idea of reaching inaccessible places.

"We Seceded Where Others Failed."

The world's first permanently occupied mountain-top observatory continues to report on the stars.

Visible below the waves are memorials to the city's Gold Rush dead.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

A shape-shifting buy-sell-trade bookstore, born to Beatnik Era spirit.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

This airfield played a key role in both World War II and the Cold War.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

This giant sculpture made of trash is a critique of society's wastefulness.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

There’s a hidden military meme engraved on the World War II Memorial.