Climb inside an iron crystal magnified 165 billion times its normal size.

Along the edge of this fountain are 365 smaller fountains that represent the days of the year.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Baroque celebration of the end of the Great Plague of Vienna.

This building has two facades of clashing architectural designs.

"Holy Wisdom" overlooks the city that became its namesake.

The remarkably well-preserved final resting place of a powerful ancient Thracian king.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

A striking symbol of the Bulgarian capital.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

Eighty million natural history specimens call this gargantuan museum home.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

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

This sprawling Jewish cemetery is one of the largest in Europe.

Cold war icon and onetime "hole" in the iron curtain.

One of downtown Berlin's last reminders of its Communist past.

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

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Started as a kitchen garden, now the second largest botanical garden in the world.

The celebrated eyesore created by starry-eyed sweethearts.