Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Mountain where Jesus was first tempted by the Devil.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This cemetery features modernist statues as strange as its name.

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

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

A beautiful but toxic fountain of mercury.

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

This charming candle shop has been in business since 1789.

The world's oldest bookshop still in operation.

An isolated village literally built into the crevices and rock formations of a mountain.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

The final resting place of the great navigator, or maybe his brother.

The morbid items in this small and hidden museum are not for the weak stomached.

At the foot of a waterfall lies a peaceful swimming lagoon and evidence of over 60,000 years of human habitation.

An exquisite collection of fairytale conveyances that puts most car museums to shame.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.