The last municipal pneumatic post system in the world was in operation for over 100 years, and may run again.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

Macabre astrological automaton clock dating to the late 1400s.

The first museum in the world devoted to sexual gadgetry.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

This museum promotes informed contraception by documenting its often secret past.

Handsomely crafted representations of our round planet.

Museum devoted to the artificial language of Esperanto.

Op-art architecture designed for happiness.

Macabre museum devoted to historical Viennese murders.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

The beautiful baroque library of the Hapsburg empire.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

An exquisite Baroque church in Vienna's old town.

The solemn exterior conceals an opulent interior of this 17th century church.

A silly medieval mural preserved on the side of a Viennese house.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.