A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

Outsider art meets paleontology at this roadside reptile repository.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

On Japan's Tashirojima Island, cats are king.

This museum devoted to the gothic author holds such interesting ephemera as his socks and walking stick.

This famous bridge twisted itself into oblivion, but not for the reason you might think.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.

This too-low North Carolina railroad trestle is still a notorious big rig executioner.

A normal, unassuming pedestrian overpass has been the demise of many, many trucks.

The tiny church offers succor to travelers driving by, but only eight at a time.

A comprehensive collection of bonsai set in a beautiful campus.

The building features one of the last remaining free-floating spiral grand staircases in the U.S.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

Every summer West Seattle experiences a housing bloom.

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

A collection of odd-shaped and quirky sounding instruments handmade by a midcentury inventor-composer.

A beautiful footbridge with over 2,000 glass sculptures along the walls and ceiling.

Native American burial mounds? Giant gopher dens? No one knows what created the Mima Mounds.

One small town in the Pacific Northwest transformed itself into a Bavarian-themed tourist destination.

This historic building provides a powerful glimpse into the lives of Japanese Americans forced to relocate during World War II.

Bonsai trees that are up to a thousand years old.

Shoreline strewn with the remains of ghostly fallen trees.

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