The longest continuous lava tube in Oregon.

The trunks of 3,000 year-old trees lurk beneath the surface of this crystal clear lake in Oregon.

You'll need cowboy boots to trek to this old-fashioned saloon nestled in a giant natural cave.

Eastern zen meets Western grit in these four little trees growing out of a rock on Lake Tahoe’s Nevada shore.

This historic estate on the east shore of Lake Tahoe was home to an eccentric millionaire (and his pet elephant, Mingo).

Historic home to one of the most famous women pioneers of the 19th century.

The largest drain hole in the world.

The sole surviving relic of the San Francisco neighborhood cobbled together from old horsecars and streetcars.

Spend a day hanging out with domesticated Russian foxes.

George Lucas donated this park to honor the birthplace of his two biggest movie franchises.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

You can row a boat through this ancient underground reservoir.

Four abandoned towers hidden above the Douglas fir forest in Washington.

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

Thousands of acres of beautiful wild landscape in the Great Basin.

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

The mysterious megaliths have enchanted and intrigued visitors for thousands of years.

The only parking meter in the entire town, it is surrounded by 100 free spaces.

Perhaps the most scandalous statue of America's first president.

This dramatic rail curve was once the target of a failed Nazi attack.

This enormous World War II relic is one of the largest wooden structures in the world.

The final resting place of the living embodiment of the famous Forest Service symbol.

Its dark depths conceal millions of rare, delicate crystal formations.

It is locally loved and ridiculed for literally looking like poop.