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

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

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

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

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

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

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

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

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

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

This sculpture pays homage to the street sweepers of Madrid since its inauguration in 2001 in Plaza Jacinto Benavente.

Artist Natividad Sánchez wrote a new ending for one of Roman mythology's tragic love stories.

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

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

The Spanish king's private bathroom embraced the idea of a porcelain throne.

On an idyllic island off the coast of Sierra Leone, remnants of the defense of the slave trade and its later abolition.

After Sierra Leone's railways shut down in 1974, a collection of engines and other artifacts spent decades hidden away in this old workshop—now a museum.

Sample sweets at an Art Nouveau candy shop that's been in business since 1874.

The last remains of one of the oldest and largest oak trees in the United States calls this state park home.

The oldest of its kind in the country, this tree sits where formerly enslaved people are said to have founded the city of Freetown.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.