Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

A gruesome and mysterious ancient sculpture of a pagan deity from the Roman occupation of Celtic Britain.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

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

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

Giant, friendly pelicans in Central London, the most unlikely of places.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

This colorful statue welcomes visitors to a Barcelona park.

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

Week-long block party becomes a competition for the best decorated street.

For more than half a millennia, this automaton has rung an hourly bell.

A magnificent, long-abandoned castle built in the wake of the reconquest of Spain.

A breathtaking and biodiverse wilderness in the mountain setting of Ernest Hemingway's "For Whom the Bell Tolls."

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

This unassuming bookstore in the heart of Madrid is one of the oldest in Spain.

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

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

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

A must for film lovers in Madrid and home to the Spanish Film Library's projection space.

Inaugurated three times, this tower offers some of the best views of Madrid.

This uniquely shaped 17th-century structure comes alive in early September.

This 47-story "M" needed 20 years to be completed

Poet Antonio Machado's former residence offers the quintessential Castilian lifestyle of the provincial towns in the early 20th century.