A signal indicates the entrance to this alley, rumored to be a meeting place for witches.

A botanical garden full of thought-provoking contemporary sculptures.

These ruins are all that remain of Tortosa’s lost coal gas manufacturing industry.

This memorial, built by fascist dictator General Franco in 1960, has been repurposed by the people of Catalonia.

Peek into a cave of giant, glimmering crystals.

Bacteria and algae give the salty water its bubblegum hue.

This enormous sardine in the Segura River pays tribute to an annual post-Lent tradition.

Originally planted by the ancient Carthaginians, this sprawling palm grove is one of the largest in the world.

Hidden underground, a remarkable 10th-century bath complex survives virtually unaltered.

Down this yellow brick road, visitors are treated to toadstool houses and massive mushroom sculptures.

Legends surround this natural rock formation that looks like a Moorish king wearing a crown.

This decorative arch symbolizes the history of this medieval village but still maintains a modern purpose.

For many years, the origin of these enigmatic artificial caves was the subject of debate among historians.

This human-made cave is one of the many snow storage chambers that supported the ice supply industry in the Sierra Mariola area.

This set of Berber granary caves is now an interpretation center for the cave window structures in the Clarino valley.

On market days, a tax collector sat in a small cave at the end of this arched bridge.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The last bastion of Roman presence north of the Alps looms over a German town.

The standard measure of Lagom, a measure of what is enough.

These ancient rune stones plucked from the countryside now call this university park home.

The marker that allows students all over the world to be late for class.

This Swedish astronomical clock was in storage for almost a century before its glorious workings were put on display once more.