All aboard the world's longest miniature railway.

Only known mainland rookery of the threatened Stellar sea lion.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

Featuring a casually threatening atmosphere along with dessert and coffee to die for.

The seamy, underground secrets of Portland's criminal past.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The wreckage of a deadly bomber plane crash can still be found near an Arizona peak.

Limestone caves with spectacular showcase chambers.

America's only nuclear missile silo open to the public.

Outsider Art Community.

The attic of a four-century-old canal house hides a clandestine church.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

Indents in the pavement are all that remain from a grisly death machine in Paris.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

This noble mash-up in eastern Luxembourg is part Medieval, part Renaissance, all castle.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

"The most colorful grottoes of the world.