Sandstone rock formations that look like they belong on the cover of a progressive rock album.

148 feet long and in the middle of a verdant forest.

One man's ambition created this psychedelic log home.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A botanically themed auditorium blooms within the world’s last operating double-decker theater.

Monasteries on rock pillars, once accessible only by frayed ropes.

The beauty of urban decay, hiding some dark secrets.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

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

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

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

The oldest Italian café in Boston, this spot also serves as a veritable museum of vintage coffee ephemera.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Tubing through a cave lit with glowworms is a magical underground experience.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

The tragic reality of a town riddled with rumors of haunts, chemical spills, and serial killers.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

Hanging over one of Japan's "hidden valleys," these vine bridges must be remade every three years.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.