A stone from Africa's tallest peak is immortalized in a Potsdam palace—but is it actually the mountaintop?

Trimmings from the record-setting tree line that surrounds Cirencester Park have been used to manufacture chemotherapy drugs.

One of London’s rare Tudor-era buildings is a fate-defying gatehouse for a church.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

A once-secret library of Freemason history in Catalonia.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

A temple to modernity, tucked away amid Barcelona's more well known museums.

This cafe offers a curated collection of treats and tipples made by monks and nuns.

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

This cemetery features modernist statues as strange as its name.

The oldest building in Madrid.

One of the best examples of the modernist movement in Madrid.

Meant to resemble a massive tree, the building is the best example of Spanish organicist architecture in Madrid.

This Art Nouveau gate still stands at the former entrance of a 20th-century Spanish writer's colony.

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

Five million people are laid to rest here, more than the population of Madrid itself.

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

This postmodern apartment block was designed to be a vertical neighborhood.

Order cookies baked by cloistered nuns in a 400-year-old monastery.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

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

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

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