Pagan monument converted to Christianity with the population.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

This star-shaped military outpost is now simply trying to protect itself from neglect.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This small chapel is built of human bones and decorated with a golden skeleton.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

Houses are tucked between, on, and underneath giant boulders.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

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

For one day every month Barcelona's Estació de França transforms into a market for model trains.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

This cemetery features modernist statues as strange as its name.

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.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

The oldest housing complex in Riga is a mini timeline of architectural trends.

3,000 market stands in five former Zeppelin hangars.