This conical hill was built as a testing ground for an engineer known as the Glider King.

Super-heavy Nazi architectural experiment.

A wunderkammer of mysterious objects and stories.

Visitors can explore the role of mysticism throughout the ages inside this interactive museum of magic.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

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

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

An eclectic collection of thousands of items owned by the sculptor Frederic Marès.

A temple to modernity, tucked away amid Barcelona's more well known museums.

This cemetery features modernist statues as strange as its name.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

A stately palace has been converted into the world's largest cannabis museum.

These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

The traditional Polish croissant, folded 81 times into the shape of a horseshoe, is a legally protected cultural treat.

The ancient Greek Titan guards this massive dam holding a lightning bolt to symbolize electricity.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

This skeletal, unfinished Gothic church once housed a miraculous masterpiece by Raphael.

This mosaic-lined medieval church was built by the world's first admiral and still holds mass in ancient Greek.

Thousands of well-dressed mummies below a monastery.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

An eerie, derelict amusement park in Berlin.

A museum which takes visitors to the côté obscure of Paris.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.