One Portuguese poet described this cape, the westernmost point in mainland Europe, as "where the land ends and the sea begins."

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

A unique seaside cave where Aleister Crowley faked his own death.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

The final resting place of the "father of special effects."

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

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

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

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

Cat art as far as the eye can see.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

A little sculpture with a large wardrobe.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

A fortified palace in the shape of a ship on the Thiou river.

The skulls and bones of thousands of soldiers line the walls of this small Italian chapel.

One of the most well-preserved castles in Italy also contains a rare medieval example of a port fortification.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.