One woman's Viking Castle on Lake Tahoe.

A huge collection of rocks, gems, and crystals.

Built in 1895, this bed and breakfast was once a hospital that served an early 1900s Gold Rush boomtown.

A rich history stashed behind an unassuming door in the heart of Gold Country.

Established in 1853, this crumbling cemetery sits forgotten on the corner of Church and Chapel in Gold Country.

The Empire Mine is "one of the oldest, largest, deepest, longest and richest gold mines in California."

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.

Largest collection of mounted dinosaur specimens in the world.

A replica that won't float away.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.

Once America's tallest structure, now a Baltimore landmark.

The Forest Service's surprisingly sophisticated collection of wildfire prevention art features America's most beloved bear.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

A haunting exhibit in a wildlife refuge center highlights threatened species and the conservation efforts needed to save them.

A benevolent, 16-foot-tall river dragon lives on a suburban lawn.

An allegorical sculpture in Maryland wears the artist’s politics on its trunk.

The Decoy Capital of the World.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.