Hidden behind Lincoln's head is a chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

This shallow pit was once used to send over 20,000 buffalo plummeting to their death.

A cemetery housing wild west legends in South Dakota.

The first declared National Monument in the United States.

See the computer’s history revealed over the course of 20,000 years.

"Polynesia on the Plains."

This historic building provides a powerful glimpse into the lives of Japanese Americans forced to relocate during World War II.

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

42nd story Pyramid shaped penthouse tops Seattle's oldest skyscraper.

Though strikingly beautiful, Seattle's other railway station is now largely forgotten.

A wall of chewing gum moonlights as collective art.

Couple's personal collection of pinball machines turned public pinball museum.

You might know it as the Overlook Hotel, but the inside is not going to be familiar.

A working model of a pressure-driven, high-speed rail whizzes around a private vineyard.

One of only five observatories in the world built to measure the Earth's wobble.

One of the largest Buddhist communities in the West sits on the site of an old hospital.