A 140-year-old castle with underground caves hidden in San Francisco.

A huge musical instrument played by the ocean.

The tiniest tiki room in San Diego.

The longest and widest floating bridge in the world.

Five varieties of trees with custom-designed grates around the trunk are planted along the route of the Seattle Transit Tunnel.

The spur that wouldn’t die.

The Denny Substation has been called "the coolest substation in the world" and sits in a densely populated Seattle neighborhood.

This quiet neighborhood is also home to a 700-ton rock transported by the last Ice Age.

Remnants of a forgotten 1920s speakeasy and Prohibition-era murals were discovered in its basement.

Always a new use for this old building.

What's that on the side of that building? Va Va Voom, it's Bettie!

A young botanist's horticultural vision realized through a lifetime of planting, tending, and collecting seeds.

An old-timey peepshow allows visitors to gawk at some of the world's most freakishly large footwear.

This Seattle museum displays the history of the telephone through an impressive collection of telecom equipment.

Spanning an elevation of 160 feet and containing 388 steps, this is Seattle's longest staircase.

The tale of a strong-willed woman who stood her ground when the commercial world came rumbling in.

A wall of chewing gum moonlights as collective art.

A colorful architectural gem in Seattle's uniquely modern Central Library.

This punny mirror of another Wisconsin attraction is exactly what it sounds like.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

A display of magnificent stained glass windows is the first exhibit of its kind.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

This float factory takes the mask off of Mardi Gras and lets visitors see where the magic happens.