A marvel of Byzantine engineering under the streets of Istanbul.

This fascinating museum in an old water tower holds the world's largest collection of Vodou artifacts from western and central Africa.

1513 Turkish world map, full of European state secrets and snarky commentary.

Large miniature theme park with 100-plus models.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

This former steel and coal plant is now a neon-lit industrial fantasia.

This small gallery nestled inside an old botanical glasshouse is a quiet place to enjoy art and nature.

This temple to the sturm and drang of Richard Wagner contains a dragon's cave and reptile zoo full of living "dragons."

Thousands of flowers create enchanting pink tunnels over the city streets.