This elaborate estate contains a stunning marble aviary, a sunken conservatory, and a magnificent music room with a two-story pipe organ.

The abandoned mine where American troops discovered a treasure trove of art and artifacts hidden by the Nazis.

A rare example of a German cemetery with traditional grave markers dating back several generations.

The ruins of an abandoned crematorium haunt an eerie deserted German cemetery.

A former Nazi lookout tower with a magnificent view of the Rhineland.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.

Berlin's old airport.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

This unique Renaissance castle was turned into a home for Nazi occultism.

Dress up like a miner and take a slide into the disco-lit depths of this once foundational salt mine.

A unique hanging cable-car navigates through Dresden, the oldest suspension railway in the world.

When German-Iraqi relations broke down, this embassy was vacated post haste.

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

This "floating railway" is one of the world's oldest monorail systems.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

Skeletons dressed in extravagant 18th century royal costumes cavort in the aisles of this German basilica.

The most visited, and possibly most controversial, museum in Germany.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

One of the most remarkable caves in all of Iceland was created by a once raging river of lava.

Every summer local children form "pysja patrols" to save young birds that have wandered from their nests.

A giant concrete orb in far north Iceland marks the ever-shifting boundary.

The oldest steel ship in Iceland has been beached for years and is now a rusting ruin.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

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