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

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

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

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

Be on the lookout for the symbolic insect all over the city.

Model Trains and Much More in Hamburg.

Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

The secret medieval communication system will whisk your words above the noise of the crowd.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

Brass plaques embedded in pavement preserve the memories of those who lost their lives at the hands of Nazis during World War II.

An ode to a soldier who came to town, fell in love, then began making his own sparkling wine.

Launched by Napoleon's soldiers more than 200 years ago, a cannonball remains embedded in the tower wall.

The inverted pyramid design of this station stands out amid Bratislava's urban landscape.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

The mysterious empty cupola behind the monumental arch points to an ancient prophecy of Delhi.

The beautiful 16th-century stepwell lies in the shadow of a famous fortress.

This opulent 16th-century Maharaja’s palace is a unique mix of Hindu and Muslim designs.