A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

This elegant arc of a waterfall marks a religious turning point.

A once grand hotel is being retaken by the wilderness it once capitalized on.

An inconspicuous footbridge beloved by San Diego locals.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

This massive redwood tree has a hole in the base big enough to drive through.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

An encyclopedic collection of mammal penises.

This family mausoleum is steeped in symbolism and looks more like a fantasy location than a grave.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

Centuries-old bridges grown from tangled roots.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Abandoned bridge hidden deep in the San Gabriel Mountains.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

Stay in a room with a view... of the bottom of the ocean.

A gargantuan crystal kingdom.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

This expansive bridge in the Canadian wilderness was originally just built for friends.

This structure among the trees was the result of divine inspiration.

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

A unique waterfall that some believe attracts the fairfolk.

The highest bridge in America was built for an almost unnervingly small amount of money.