A series of five defunct panopticon prisons in Cuba.

Paleoamericans built these ancient walls high in the Colorado Rockies as part of an extensive hunting system.

The giant stump of the once towering cottonwood where Ute people held tribal meetings.

The oldest operating cemetery in Denver is the eternal home of some of the Centennial State's most famous residents.

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

Wall to wall taxidermy at Denver's oldest and most exotic steakhouse.

Rather than a run-of-the-mill franchise hotel, this lodging has been decked out in dinosaur decor.

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

This naturally-sourced hot spring is now home to a clothing-optional resort.

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

A celebration of all things tacky, garish, and bizarrely creative in the Romanian capital.

Climbing to the top of the cathedral's bell tower offers sweeping views of these medieval ruins.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

Ride a boat through this magnificent underground world, which now doubles as a theater.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

The world's largest maze is a nature park with nearly 200 decision points.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

Raging waters have created a strange geological site that looks like something off of a progressive rock album cover.

A long, winding trek rewards you with a gorge so captivating it inspired a painting in the Tate.