Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

A medieval military street hidden beneath a charming French fishing village.

Artist's eccentric property excessively decorated with found objects and work of his own.

This massive blockhead sculpture hides an entire library.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

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

An ancient Egyptian temple in the middle of Madrid, Spain.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

The earliest known map to show America, discovered by accident at a Paris bookshop.

A lush indoor jungle fills this bustling Madrid transportation hub.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

This lucky bronze frog was gifted to Madrid by a casino.

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

Just like in Hollywood, Madrid has also a forgotten walk of fame.

It's always game time at Stockholm's only museum devoted solely to video games.

It houses the remains of a 17th-century version of the Titanic.

A little-known cafe in an old copper bridge tower with 360-degree views of the harbor.

Six beautiful wooden giants are hidden around Copenhagen.

A stunning silver lining to global warming's gloomy cloud.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

18th century opera in its original splendor.

This luxury hotel suite is located deep in the bowels of an old mine.