Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

Legend says this sacred tree was a gift from goddess Athena.

A sharp sculpture made of thousands of pieces of jagged glass.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

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

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

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

A fairy tale castle in modern Rome.

The final resting place of the poets Shelley and Keats.

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

Architectureal fantasy quarter of Rome.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."