Collection maintained by the legendary designer.

This "mathematical tower" was an observatory, early skyscraper, and place to reflect on all of nature and the cosmos.

Rippling sand dunes frozen in the Arizona rock.

See massive fossils that are over 200 million years old in northeastern Arizona.

Three-story slide through the New Museum.

One man's stunning attempt at eco-friendly living.

Display that gathers the basic elements of the universe in one convenient location.

A bizarre house filled with an astounding array of collections.

Outsider Art Community.

"World's largest scrap metal sculpture" stands in an outdoor sculpture garden in the middle of Wisconsin.

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

Space-age monument to an early 20th-century uprising.

The longest continuous lava tube in Oregon.

A volcanic fissure over two miles long and up to 70 feet deep.

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

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

Treehouse motel and treehouse-building school.

Two churches shoot bottle rockets at each others' bell towers in an unusual Easter celebration.

Museum houses an impressive display of the origin and artistry from the now-quaint invention's history.

A semi-scholarly approach to sex.

After Havre burned down, the best place to build was under the ashes.

An vast warehouse of everyday treasures in Berkeley, CA.

A cabinet of curious mathematical models and old calculators.

A reproduction of earth's many biomes.