Louise Bourgeois' 30-foot-tall steel spider sculpture.

This slumbering beast honors the Bavarian soldiers who died in Greece during a 19th-century typhoid outbreak.

Eighty million natural history specimens call this gargantuan museum home.

The atmospheric road was never meant to be so creepy.

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

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

An emerald-green grotto just a short trip from Austin.

A beautiful geyser under environmental threat.

Quite simply the largest tree in the world (by volume).

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

When it was built in 1929, this historic bridge was the only place to cross the Colorado River for 600 miles.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

A museum dedicated to the alleged Roswell Incident.

The ghost town that ended up on Ebay.

These fantastically named natural pools look like something out of a Scottish myth.

A frozen oasis lies beneath the scorching New Mexico desert.

This replica of the Greek structure is in the heart of Nashville.

An encyclopedic collection of mammal penises.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

A huge musical instrument played by the ocean.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

A creepy tree with a local legend that inspired a nearby theme park ride.