Erotic art covers the walls of the largest ancient pleasure palace.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

Ancient snack bar of the Roman Empire re-opened.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

Beneath the city of Lourdes, France is a massive, concrete church.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

A radio telescope for listening to the stars, based in one of the cloudiest countries in the world.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

The struggle of a small Dutch island against the sea.

Go inside a revolutionary, cage-less zoo where 35 species live and some of them roam free alongside their human visitors.

This giant wire frame man sculpture is crouched in contemplation.

Building Men of War and Indiamen from Holland's Golden Age.

For the holidays, the tallest broadcasting tower in the Netherlands turns into one of the world's tallest Christmas trees.

The world's longest wildlife overpass provides Hilversum's critters with a safe alternative to trying their luck on the roadway.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

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

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

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

Jesus' footprints and the first catacombs in the world.

A Nesting Doll of Churches.

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

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

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

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.