The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

This settlement on the original Transcontinental Railroad began by harvesting timber, but transitioned to a forgotten 19th-century industry: harvesting ice.

This graveyard is the eternal home of many brave pioneers who settled the Great Northwest.

This unassuming cheese empire in rural Oregon churns out more than 150,000 pounds of cheese each day.

This great stone guardian of the forest is a relic from the land's volatile volcanic past.

Formerly secret, precariously perched boulders.

This strange hill on Old Fort Road where gravity works in reverse has been fascinating locals for years.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

A beautiful 62-acre Catholic shrine and botanical garden.

The seamy, underground secrets of Portland's criminal past.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

A massive sea stack famous for its appearance in The Goonies.

100-year-old shipwreck you can walk up to at low tide.

The longest continuous lava tube in Oregon.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

Treehouse motel and treehouse-building school.

Rising out of miles of farmland, these buttes are sometimes called the world's smallest mountain range.

One of the largest fleets of armored vehicles in the world, sitting out in the California desert.

This little museum has an exhibit devoted to the elusive forest denizens.

The oldest orange tree in California spawned a generation of citrus farmers.

Secret Manor, a house full of legends, the least of which is the haunting of long-deceased ladies of pleasure.

Home of what was the largest hydraulic mine in the world, producing gold and the first diamonds in the U.S.

This abandoned motel doesn't welcome guests anymore, but decay and a creepy atmosphere still call it home.