This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

A space dedicated to contemporary art and culture, co-chaired by fashion icon Miuccia Prada.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

The mark of the Devil's horns on a marble column in Milan.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

Fortified medieval tower house with lovely roof garden.

A stunning cemetery famous for its extraordinarily delicate & lifelike mourning sculptures.

Museum celebrating the ocean, with the largest wunderkammer dedicated to sea exploration.

What if all public housing projects had been designed by "the Pygmalion of modern architecture," not only their prototype?

Sky ships, planes, and portraits left as unique tokens of hope and thankfulness.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

The first green space constructed on an elevated viaduct.

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

The oldest stone house in Paris was built by its most famous alchemist.

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

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

Notorious artist squat renovated into legal studios.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

A massive volcanic plug is now a protected area that hosts a number of bird species.