Thousands of Mexican Free-Tailed Bats soar around an abandoned storm drain at sunset each summer.

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

A self-built castle made by a mysterious man.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Concrete crosses scattered across the Arizona scrubland which were used to align spy satellites.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

Come for the pizza, stay for a performance on the world's largest theater pipe organ.

A volcanic landmark located on an Ice age lake bed.

This extinct shield volcano is the lightning rod of the Cascades.

A botanic garden full of trees twisted into fantastic shapes and positions.

A public fountain that spouts "health water" from a nearby spring.

Shakespeare has been brought to life in this open air theater for the better part of a century.

A forensic lab dedicated to fighting crimes against wildlife.

Before it was abandoned and left to rust alongside the road, this riverboat starred in a John Wayne movie.

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

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

A vertically floating hemlock controls the waves and weather at Crater Lake.

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

Bits and pieces from the ill-fated Donner Party's winter cabins.

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

A train tunnel that was made obsolete by the dam it helped create.

Tracing a path of more than four miles around a frozen lake, this is the longest skate trail in the United States.

An artist sees trees as a medium for sculpture.

This folk art dinosaur was almost pushed to extinction due to lack of a building permit.