The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

Former farm staffed by mental patients is now a public park.

Essence of hound's tongue and tincture of bloodroot are just the tip of the herbalist iceberg at this beautiful, impressively-stocked apothecary.

A comprehensive collection of bonsai set in a beautiful campus.

This 22-acre botanical garden is home to the largest collection of rhododendrons in the world.

The gravestones in this lost burial ground were bulldozed and replaced with houses and a dog park.

An enclosed rotunda at the Henry Art Gallery in which viewers can look up and see the uninterrupted sky.

Every summer West Seattle experiences a housing bloom.

Deep into the lower floors of Pike Place, find a date with fowl fate.

A crumbling cliffside ruin hidden in the woods.

An electrifying collection of gadgets and literature from the 16th through 20th centuries.

Stones speckled along Harris Avenue reveal hidden nuggets of the past.

Sleep beneath the big screen at this old-school movie theater.

Largest collection of mounted dinosaur specimens in the world.

This geothermal hot spring hides beneath a slowly growing mineral dome.

An absolutely beautiful 200-foot stained glass installation traces the evolution of knowledge.

This collection started by a Cornell professor once held more than 600 human brain specimens, including the one that belonged to its founder.

This local landmark is home to art galleries and the area's only community darkroom.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

This tiny Hawaiian island is slowly coming back to life after being bombed during naval training exercises.

Once a year, thousands of naked cyclists flood the streets of a Seattle neighborhood.

This unique Seattle structure was designed to be the greenest commercial building on the planet.

Always a new use for this old building.

This remarkable collection devoted to the study of fish includes 1 million preserved specimens from all around the world.