The only castle in North America to ever house European sovereigns.

Part bookstore, part café, and part forest.

Frida Kahlo's childhood home, now a museum of her life and works.

An archeological treasure trove stumbled upon by a couple of children.

Giant topiary dog once played a role in a terrorist bomb plot.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

Chemical fertilizer in agriculture's origin story begins here.

A complicated contraption for telling time by the moon.

A sweet symbol marks the place where torturous executions were once carried out.

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

A small literary museum remembers the life and works of the author of The Thirty-Nine Steps.

Construction of Barcelona's iconic (but controversial) church is expected to be 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.

Go inside to really appreciate this 500-year-old technological masterpiece.

In the world's oldest university is a stunning 17th century anatomical theater carved from spruce.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

An island filled with hundreds of hanging, decomposing, decapitated dolls.

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