This curious building hides eclectic details like medieval gargoyles alongside naked angels and Art Nouveau mosaics.

This semi-secret storybook hedge maze is also the oldest garden in the city.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

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

An ancient Egyptian temple in the middle of Madrid, Spain.

A sculpture serving as an homage to Pope John Paul II.

Climb the dead electric pylons of Messina.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Massive galleon from a box-office bomb docked in Genoa.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

An ancient rogue artist community hidden next to one of the world's most glitzy and glamorous cities.

A space dedicated to contemporary art and culture, co-chaired by fashion icon Miuccia Prada.

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

When this funny little building went up in the 19th century, most people thought it would simply fall over.

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

A medieval fresco which reminds visitors that death will come for us all.

Every inch of this chapel is covered in craftsmanship from across the world.

Da Vinci's equestrian statue, 500 years in the making.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

This former fascist summer camp was abandoned for decades.

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

The highest waterfall in Italy is only "turned on" five times a year.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.