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

One of the oldest living oak trees in the Southeast.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

This magnificent stepwell is designed as an inverted temple and adorned with 1,500 sculptures.

Crawl through the hole in the middle of this stone to break off a bad relationship or initiate a good one.

These four islands right offshore have waterfalls, colorful lights, fancy buildings, and a secret purpose.

Where the sleeping monsters of Scotland's oil industry are left to rust.

Castro's communist ice cream mothership has been serving five-scoop "salads" for over 50 years.

The world's largest sticker ball weighs in at a mighty 231 pounds.

The palace of the King of Kings, burned by Alexander the Great.

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

The short-lived railroad town in central Oregon has been abandoned since the 1930s.

Enchanting cave with a river crashing through the roof.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

This large maar crater in Oregon is the bigger brother to Hole in the Ground.

A volcanic fissure over two miles long and up to 70 feet deep.

Massive crater in central Oregon.

A massive rock in the surf steeped in legends.

Communism's topsy-turvy effect on Poland has been brought to life in this wacky tourist trap.

These molds for fiberglass statues have formed an eerie, accidental sculpture park.

A concrete block embedded with thousands of pulled teeth was created by a local dentist to memorialize his dog.

A century-old cabin off of Highway 30 touts an unusual construction material: dinosaur bones.

An extraordinary natural landscape of mountains, waterfalls, and rocky cliffs riddled with tunnels.