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

Sweden's oldest animated sign is still lighting up the skyline today.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

Jesus' footprints and the first catacombs in the world.

2300-year-old Roman road connecting the empire.

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

The yawning maw of this pagan visage is said to bite off the hands of liars.

The underground sanctuary of a mysterious ancient cult.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A massive Montreal stadium that has seen nothing but trouble since its inception.

A Montreal deli that was so beloved that it was allowed to circumvent their laws of language.

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

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

Floating swimming pool within a moored vessel.

When German-Iraqi relations broke down, this embassy was vacated post haste.

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

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