Op-art architecture designed for happiness.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

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

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

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

Mountain where Jesus was first tempted by the Devil.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

Cat art as far as the eye can see.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

The celebrated eyesore created by starry-eyed sweethearts.

This little-known relic crypt holds stolen parts of a Roman Empress.

Unconventional site where the tracks of Zurich tramcars intersect.

A six-ton wedding present for the King of the Scots.

A 18th century graveyard and its astonishing cortege of macabre iconography.

A book bound in the skin of an infamous criminal, along with countless other specimens.

The final resting place of soldiers' loyal canine companions.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

360° views of the city plus five floors of optical illusions and hands-on science.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

19th century museum with an eclectic mix of curiosities, from Egyptian artifacts to items on archery history to the skull of the world's oldest horse.