Rustic natural hot springs in the deciduous rain forest.

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

The highest point in Iowa, while not that impressive to mountain states, has earned its own monuments.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

This zombie-themed restaurant stands out in the heart of corn country.

A warning to the weak-kneed: This narrow bridge does its swinging eight stories high.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

An off-the-beaten path cave with an underground lake.

This huge dam across the Colorado River caused an armed standoff between two U.S. states.

A small canyon with petroglyphs and a seasonal waterfall, only a short hike from the remnants of old Route 66.

This ancient trail has claimed the lives of over 2,000 people.

The lost ruins of the forgotten ferry lie hidden beneath the silt.

Hike the unusual hoodoos and rock formations that form this little-known natural wonder.

This old selenite mine is dotted with tiny crystals that make it shimmer like it's covered in glitter.

The remains of this hell for leather wild west town can still be found in the Arizona desert.

The eroded core of an ancient volcano is now accessible by a short hike.

A partial tunnel blasted into a steep ridge is all that remains of a failed railway across Arizona.

The cinder cone volcano with a less than complimentary name.

A geological mystery on Camelback Mountain.

This giant steer-skull edifice refuses to die.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

An urban laboratory.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.