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

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

A varied collection of brains in alcohol.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

This East German military command bunker was ready for World War III.

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

From Ancient Rome to WWII, Neupfarrplatz has over 2,000 years of history underneath its main square.

Hamburgers are intensely proud of their tunnel beneath the river.

When a medieval fire claimed the original St. Stephen’s Cathedral, it sparked a pattern of unquenchable organ building.

An elegant chandelier hangs over this ancient sewer chamber, now open for concerts and public tours.

This former Nazi castle was built as a school to train what would have been the future of the Third Reich.

In 1830, cemetery workers in Cham unearthed a chamber housing thousands of skeletal remains from the 13th century, which can still be viewed today.

The resting place of 18th century German mummies.

Wax models of disease and deformity are on display at this German medical museum.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

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

A 12th-century fortress containing some of Berlin's oldest buildings.

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

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

This temple to the sturm and drang of Richard Wagner contains a dragon's cave and reptile zoo full of living "dragons."

The footprint of a frustrated devil in Munich's Cathedral.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.