One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

A hidden three-foot-wide house separates these two regal churches.

An early work of the architect Álvaro Siza Vieira, these swimming pools blend into the beach.

The oldest Roman lighthouse still in use.

Giant granite sculptures representing family on the northern coast of Spain.

This enchanting green space houses a labyrinth lined with toxic plants.

Made up of 3,200 recycled glass bottles, this tree pays homage to Asturia's love of cider.

A magnificent place to see authentic paleolithic cave paintings that are an astounding 33,000 years old.

These primitive rock paintings include a very beloved depiction of a woolly mammoth.

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.

This beautiful spit of land was once the summer playground of the king of Spain.

Giant topiary dog once played a role in a terrorist bomb plot.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

An architect transformed this abandoned cement factory into his castle-like workshop.

A science fiction-inspired apartment building designed by a famous Spanish architect.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

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

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

This cemetery features modernist statues as strange as its name.

A 66-million-year-old rock formation stands tall over Mumbai, offering stellar city views.

An architectural marvel that combines Gothic architecture with Indian elements.

Mumbai's angel.

An explosion of natural color known as "the river that ran away from paradise."