A restaurant and observation deck built in a unique broadcasting antenna.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The "Prussian Versailles" that is as glorious today as when it was built.

Walk through Czech history in Prague's largest graveyard.

All unmarked mute swans on the Thames are owned by the Queen per a tradition that began in the 12th century.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

Sometimes an island, sometimes a rocky outcropping connected to the world by a tiny suspension bridge.

The bones of the Biblical Magi traveled to Constantinople and Milan before landing in their current home inside an elaborate golden reliquary in the Cologne Cathedral.

Each year melting snow turns these Austrian hiking trails into scuba zones.

A series of haunting wooden totems are hidden in the woods surrounding a German environmental center.

The site of Austria's biggest concentration camp now honors its victims.

This watchtower once presided over the Berlin Wall.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

Some of the greatest minds in the history of Hungarian art and science converged in this café.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A haven for book enthusiasts across the street from Retiro Park.

The remains of the second-oldest zoo in Europe can be seen within these library gardens.

Commonly acknowledged as the only public monument to the Devil himself.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

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

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

The facade of this 16th-century building is decorated with carvings of 300 seashells.