Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Two stunning 17th-century libraries and a cabinet of curiosities.

Macabre astrological automaton clock dating to the late 1400s.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

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.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A little sculpture with a large wardrobe.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.