The site of the Wellington avalanche, one of the America's worst railroad disasters.

Site of the greatest known waterfall that ever existed.

The illuminated falls are a gem in North Cascades National Park.

This long, dark tunnel is open to hikers, but those without lights are known to get confused even on the straight path.

An obscure waterfall that looks like something out of a fantasy novel.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

A whimsical village of unique treehouses resides in a Washington forest.

An extraordinary mixture of natural beauty and man-made phenomena.

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

Stroll through a wonderland of stupendous moss-covered trees.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.

The first park built over a freeway is a brutalist masterwork.

A walk through the historic city center, under the streets of Seattle.

Pick up all of the cosmic knick-knacks under the sun or take a creative writing course, all offered in this novelty storefront.