Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

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

The restored and active Victorian-era final resting place of San Francisco.

Created in 1972, the famous sculptor's intricately detailed monument to San Francisco is overflowing with city landmarks.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

A Barbary Coast watering hole built into a Gold Rush shipwreck.

Faceless white figures loom over the city from the rooftop.

Noble beasts perhaps, but not the Emperor's dogs.

Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

A shining, cold, black organ lies in San Francisco's financial district.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."

The palatial McDonald's that inspired Wesley Willis.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

To find the "unicorns of the deep" you've got to go downstairs.

A monument to the art of slicing people open.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

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

At 207 feet, one of the world's longest continuous escalators.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.