A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

A Nazi concentration camp and Anne Frank's place of death.

The hidden jewel of Disneyland: a members only playground for the Disney elite.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

Slaughterhouse Five opens its dank doors to fans of Kurt Vonnegut.

A striking 12th-century-style castle built on the edge of a cliff.

The prototype for all Nazi concentration camps.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

The private clubhouse for the members of the Academy of Magical Arts.

A library of only unpublished manuscripts.

This blowhole is supposedly caused by a trapped monster.

This WWII plane died a quiet death, and is now a garden eel playground.

A once-glowing grotto at the bottom of Waikapalae Wet Cave.

This black shoreline is made up of exploded lava particles.

Watch the newest land on the planet form before your eyes.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

A tunnel of hardened lava along Maui’s famous Road to Hana.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Former meatpacking facility turned vertical farm and sustainable business complex.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

The site of Paul Revere's historic two lantern warning.