Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

This massive and eclectic collection is filled with thousands of sculptures, masks, and assemblages.

A small town hallucinates en masse - Bad bread, or CIA science project?

Inside this Jewish cemetery is a memorial to soldiers who deserted the German army and were executed.

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.

The commemorative stone column conceals a secret laboratory.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.

A flourishing garden with pigs, donkeys, goats, rabbits, guinea pigs, chickens, ducks, and sheep.

A domino effect created with Britain’s iconic telephone boxes.

The remains of an ancient Roman teenager are memorialized at the base of a modern London landmark.

A famous burial ground with a history both grim and literary.

Bronze sculpture celebrating the relationship between Churchill and Roosevelt.

The Columbia Road Flower Market is now open every Sunday, rain or shine.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

This hidden green space is the city's second largest conservatory.

A cluttered and astounding collection of antiquities and curiosities.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.