Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

A massive line that stretches across the floor of Bologna’s largest church was created by a 17th-century scientist to measure the movements of the Sun.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

This building features dozens of faces along its facade, although one is a bit chilling.

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

A striking memorial recalls thousands of Bolognese men and women killed fighting fascists in World War II.

A beloved local artist has been honored with this statue of a man emerging from a toilet.

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

When built, the technology here made Souter the most advanced lighthouse in the world but, nowadays, it is a tourist attraction and a (reputedly) haunted vacation spot

The largest stretch of the Berlin Wall is right on top of the former SS headquarters

Luxembourg's most popular statue since 1923 has been missing for... 26 years!

The memorial to this brutal battle between the English and the Scots has a surprisingly humble origin.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A series of markers along one side of an Amsterdam canal memorialize the Jewish residents from the other side who died in the Holocaust.

This viaduct looks more like something from a Victorian dream.

A rocky Irish outcropping with a history of wealth, conflict, and ruin.

A life-sized imperial army, buried in battle formation, has stood underground for over 2,000 years—built not for war, but for eternity.

An angel that hatched from an egg!

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

Things aren't quite what they seem at this mind-bending museum.

This former KGB building is now a museum memorializing the people who suffered during the Soviet regime.

An abandoned masterpiece of Soviet Brutalist architecture.

The largest coin pyramid in the world is a carefully balanced stack of over 1,000,000 pieces.