This ancient Roman cistern has been the source of many legends throughout the centuries.

At least according to the Guinness World Records.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

This influential Renaissance-era library was once the haunt of kings and monks.

The remains of a convent turned military barrack in the heart of Madrid.

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

This enigmatic Iberian sculpture of uncertain origin may have once guarded a burial site.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

These ancient artifacts are a testament to the enduring significance of the bull in Spanish culture.

An iconic and controversial ancient Iberian funerary urn with a hauntingly penetrating gaze.

This historic fountain is a favorite neighborhood meeting point.

The oldest vestiges of Madrid found here, have been incorporated into this new museum.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

A rare set of strings by famed instrument maker Antonio Stradivarius is on display in the Royal Palace.

A small but stubborn relic of Spain’s turbulent past hides in plain sight.

After the queen of Spain had a dream where these statues fell and crushed her, they were removed from the palace and given new homes around Madrid.

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

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

The remains of the second-oldest zoo in Europe can be seen within these library gardens.

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

Commonly acknowledged as the only public monument to the Devil himself.

A haven for book enthusiasts across the street from Retiro Park.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."