A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

Norway's oldest cathedral still in use.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

Home to three historic ships from the age of Vikings.

A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

Behind medieval walls in a corner of bustling Palermo is a breathtaking former mosque once inhabited by a wolf-taming hermit.

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

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

Ride a boat through this magnificent underground world, which now doubles as a theater.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

Stumbling upon this whimsical wooded garden is like stepping into an enchanted forest full of philosophical musings.

This seaside Italian village doesn't just look Escher-esque, it actually inspired the mind-bending artist.

Geometry and mystery come together in an epic show of octagonal masonry.

Beautiful views and Roman-style statues on the Italian coast.

A factory director designed what was the world's longest suspension footbridge in 1923 so his employees could get to work safely.

A fairytale-like medieval church perched atop a rocky cliff on Italy's "Coast of the Gods."

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

This precariously perched fortress was once ruled by a crow-worshipping baron.

A massive natural rock arch gives the Tuscan mountain its own window to the sky.