Op-art architecture designed for happiness.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

A monument to the man who almost killed Hitler.

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

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

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

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

The most visited, and possibly most controversial, museum in Germany.

The world's largest "Christmas tree" is illuminated by hundreds of lights stretching 2,000 feet up the slope of Mount Ingino.

A map of Italy made entirely of trees.

This amazingly preserved Doric temple was abandoned before it was ever completed.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

Mysterious tombstones thought to be remnants of Atlantis.

Fountain where visitors can earn a license to be mad.

Behind medieval walls in a corner of bustling Palermo is a breathtaking former mosque once inhabited by a wolf-taming hermit.

Every inch of this chapel is covered in craftsmanship from across the world.

A spiritual sanctuary in a natural cave.

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

Water and windows define this defensive Italian well.

This mosaic-lined medieval church was built by the world's first admiral and still holds mass in ancient Greek.

Southern Italy's spinning top village.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.