The medieval castle built as headquarters for the Pope's secretive Knights Templar.

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

In addition to showing films, this one-screen arthouse cinema from the late 1940s is a museum of old film equipment.

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

Eat the ultimate iteration of Portugal's most beloved pastry.

Macabre astrological automaton clock dating to the late 1400s.

According to tradition, King Phillip II supervised construction of the seat of his empire from this seat carved into rock.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

Built to celebrate the glory of a new queen, this forgotten monument has moved around Madrid three times, reflecting 200 years of political whims and city redevelopment.

The last king of Poland was interred in this church nearly 200 years after his death.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.

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

Catacombs turned marketplace.

This museum tucked below a charming cafe gives a brief snapshot of photographic history.

A naturally mummified 2,000-year-old man.

A measuring mishap led to these artificial stone ladies losing their stomachs.

Visit the grave of a famous feminist author and the mother of Mary Shelley.

This sculpture encompasses the emotion of rail travel.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Ship-sized kinetic sculptural fantasy.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

The remains of an ancient Roman teenager are memorialized at the base of a modern London landmark.

Scattered throughout London are ancient remnants of the city's former bounding wall.