You have to love a museum with a truly dedicated focus. A focus on Superman, for example.

The world's longest known cave system.

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.

A short nature trail winds through the greatest works of poet Robert Frost.

The residents at this Yellowstone wildlife park will certify your cooler as "bear-proof."

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

Take a hike to this remote, scenic tea stop in the Canadian Rockies.

The house where the writer spent his formative years.

Legend has it the commander of the defenders drew a fateful line in the dirt with his sword just before the final battle.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A Rocky Mountain city provides a happy ending for a pinto pony and his Brobdingnagian red chair.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

The secret city built by the Manhattan Project.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

An average of 33 million gallons of water pour out of the collapsed cave at the heart of this spherical spring.

It's as if the herds walked straight out of a fairy tale into the Missouri wilds.

Where the author wrote her beloved "Little House" books.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Ever wanted to can Spam?

The fastest mail service in the west is tracked and memorialized along this 1,400 mile trail.

Created by a local artist, these quirky sculptures each have their own names and personalities.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.