More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

A Nesting Doll of Churches.

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

2300-year-old Roman road connecting the empire.

The underground sanctuary of a mysterious ancient cult.

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

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

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Baroque celebration of the end of the Great Plague of Vienna.

The beautiful baroque library of the Hapsburg empire.

Brussels' favorite peeing boy has a sister.

A little sculpture with a large wardrobe.

Meet the bronze beloved pet to a family of famous peeing statues.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

The celebrated eyesore created by starry-eyed sweethearts.

This bridge was constructed from the rubble of the infamous Bastille.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

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

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The very center of Paris is surrounded by a bevy of strange good luck rituals.