Two stone columns flank the grand Venice square, but there were supposed to be three.

A twisted steel beam from the wreckage of the World Trade Center is the centerpiece of this memorial for those who died on September 11, 2001.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

The oldest botanical garden in the world that technically isn't the oldest.

The incorrupt tongue of the patron saint of lost things is venerated in this basilica.

One of the largest squares in Europe contains an entire artificial island.

The tomb of the mythological founder of Padua is not hidden in some obscure crypt, but stands right in the middle of the city square.

One of the world's oldest working clocks is curiously missing the Zodiac sign of Libra.

This zoological museum began as the first great curiosity cabinet.

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

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

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

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

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

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A pair of gigantic baby heads greet passengers at Atocha Station.

A curious memento mori hangs in the magnificent Cathedral of Segovia.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Artist Natividad Sánchez wrote a new ending for one of Roman mythology's tragic love stories.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

A giant bug impaled on a 75-foot-tall needle.

A little sculpture with a large wardrobe.