A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

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

The final resting place for the remains of 143 Habsburg royalty.

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

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

An exquisite Baroque church in Vienna's old town.

More than a millennium's worth of municipal records preserve the political history of Austria.

Op-art architecture designed for happiness.

Dine amidst exotic plants at this former royal greenhouse.

Designed as a reminder of one of the darkest moments in Austrian history.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

Apartment complexes built into huge repurposed natural gas tanks.

Physicist’s epitaph provides final confirmation to a career of turmoil.

The resting place for anonymous victims of the Danube's dark waters.

Collection dedicated to funeral rites, equipment, and mourning rituals of the Viennese.

The mark of the Devil's horns on a marble column in Milan.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Secret refuge and museum of the Duke of Florence.

A hidden workshop for creating and restoring Papal mosaic masterpieces.

If you want to talk to the Pope you will have to stare down this surreal vision of Jesus rising from a nuclear hell.

The Vatican's secret porn-festooned bathroom was painted in erotic murals by one of the greatest artists of the Renaissance.