An architectural oddity hides in plain sight on this iconic London bridge.

The ritual has been performed uninterrupted for nearly 700 years.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The majority of the museum's large collection is held in a storage space open to the public a few times a year.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

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

An early 20th-century bullring converted into a modern shopping center.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

A 16th-century Andalusian palace.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

The world's largest wooden structure.

The final resting place of the great navigator, or maybe his brother.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

A charming beach town in Turkey captures all the colors of the rainbow.

These artifacts were discovered during the construction of the airport, with some dating back to the Neolithic period.

A crushed gate and giant bronze head serve as a reminder of Greece's fight for freedom.

What once sat in the world’s spotlight is today a largely disused ghost complex.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.