A tiled, multi-level garden of survival in Lyon.

A forgotten "city of water" underneath the famous Trevi district.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Architectureal fantasy quarter of Rome.

A historic arboretum and non-conformist, non-denominational park cemetery.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

This massive library holds what was once the largest book collection in the world.

Abandoned railway line circling the city of Paris.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

With a history of slaughter, feast, and famine, remnants of the pork industry decorate this area--even its church.

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

Monuments don't get much more metal than these three giant viking swords planted in a Nordic hill.

Walk behind a 50-meter-high waterfall.

Europe's largest prehistoric mound – burial site of a legendary king?

An art world insider finds himself battling for his artistic home.