This frozen tunnel in central Alaska is both an engineering feat and a valuable climate classroom.

Gorgeous cave resemble a winter wonderland.

Upside-down trees serve as natural flower pots in this hanging garden of Alaska.

The king of U.S. high points towers over every other peak on the continent.

Internationally recognized group that works to protect the wolf and educate the public about its plight.

North America's first frozen mummified remains of an ice age steppe bison, the 36,000 year-old mummy named "Blue Babe."

Don't be a grizzly man. Get personal with Alaska's wild bears from the safety of this conservationist camp.

A rare kind of blue bear can be found chiefly in the national park that shares their name.

The final resting place for the famed creator and narrator of "The Twilight Zone."

A mummy and sarcophagus are part of the many wonders in this library's collection.

A reproduction of a giant humanoid "fossil," a hoax buried locally for construction crews to find and gain national attention.

This exhibit allows visitors to wander through the interior of a replica Ice Age glacial cave.

This art center is way beyond your average pumpkin-carving operation.

The quarry was abandoned over 100 years ago, after a massive ammunition explosion ended in tragedy.

A carriage house converted into what resembles an 11th-century English manor house

The final resting place of Harriet Tubman and other famous historical figures.

Designed to commemorate the founding of the first settlement in Delaware.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

This collection of odd proofs of concept is like taking a walk through the imagination of a Victorian engineer.

A desiccated merman and a walrus penis bone are among the oddities in this eclectic collection of shipwreck treasures.

What began as an art installation is now the private drinkhaüs for a brewery's employees.

It would take 35 firetrucks to fill this enormous glacial pothole.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

The Boston square dedicated to the dark poet who was born nearby.