This 19th-century fountain's namesake animal isn't what you think it is.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

Inside this church are the alleged remains of the patron saint of lovers, epileptics, and beekeepers.

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

This embalmed man is one of the best preserved mummies from the Canary Islands.

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

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

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

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.

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

Part of the medieval watchtower is displayed in an otherwise ordinary parking garage.

This small museum tucked within a subway station holds pieces from Madrid's past.

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

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Originally used to sell brandy, the bull-shaped billboard became an iconic symbol of Spain.

This technological marvel is one of the world's first 3D-printed bridges.

The mysterious large white cross visible from the runway is a memorial to a massacre during Spanish Civil War.

A towering monument in Spain has proven to be more labor-intensive than initially planned.

A huge cathedral single-handedly constructed by one eccentric monk.

One of the world's oldest universities houses an incredible collection of anatomical models, mummified body parts, and human bones.

The morbid items in this small and hidden museum are not for the weak stomached.

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