A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Floating swimming pool within a moored vessel.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

An eerie, derelict amusement park in Berlin.

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

Berlin's old airport.

Metro station with a claim to rock n' roll fame.

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

An old department store turned Nazi prison turned artist commune.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

Terrifying derelict military hospital once housed a recuperating Hitler.

A Nesting Doll of Churches.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Jesus' footprints and the first catacombs in the world.

2300-year-old Roman road connecting the empire.

The final resting place of the great navigator, or maybe his brother.

Single runway interrupted by a busy road that cuts across its middle.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

Ancient mysterious ruts carved in the bedrock.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

The topiary maze at the Habsburg hunting lodge.

Op-art architecture designed for happiness.