Apartment complexes built into huge repurposed natural gas tanks.

A unique opportunity to stay the night in retrofitted sections of sewer pipe.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

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

The prison where Hitler wrote "Mein Kampf," and 278 Nazis were later executed for war crimes.

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

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

A small square plaque marks a failed assassination attempt that could have changed history.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

This centuries-old Italian chapel hangs midway down a sheer cliffside.