A 1940s nuclear reactor built to produce plutonium for the Manhattan Project.

Siberian husky that delivered a life-saving antitoxin.

An Alaska livestock farm devotes itself to harvesting wool from creatures that once ran with mammoths and sabertooth tigers.

Considered by many to be one of the most dangerous highways in Alaska.

In 1912, this idyllic Alaska landscape was blown apart in the largest volcanic eruption of the 20th century.

The now-serene site of the largest earthquake ever recorded in North America.

Orcas on display and in the water.

A walk through the historic city center, under the streets of Seattle.

A giant Troll lurks under one of Seattle's oldest bridges.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

This nondescript tunnel has been featured in a number of iconic movies, from “Roger Rabbit” to “Back to the Future.”

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

When World War II came to Canada, Fort Péninsule was part of the first line of defense for Allied shipping convoys.

The oldest continuously-operating Chinese restaurant in the United States has been in business since 1911.

These subterranean models show Mexico City's central square during three different eras.

Once home to an aristocratic family and a workers' organization, this intricately tiled building now houses a chain restaurant.

The unique collection often goes unnoticed by visitors focused only on the archaeological objects.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

An Inca spa, military outpost or maybe… both?

A remote candy-striped mountain in the Peruvian Andes straight out of the pages of Dr. Seuss.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

It took 82 years and four different plaques to finally get the story right.