The remaining relics of the patroness of Paris lie in a chapel under a striking double spiral staircase.

Former hunting lodge of a duke who was an avid collector of impressionist works.

Saintly bones pressed into a wax effigy of a Catholic superstar.

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

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

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

The narrowest street in Paris.

The first green space constructed on an elevated viaduct.

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

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

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

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

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

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

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

There has been an astronomical clock on this spot since the 14th century.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

On high feast days, the entire blue-glass front of this modern church opens up to reveal the small wooden church inside.

The telescope that discovered Neptune.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

The patron saint of spinsters grasps a container of dried blood.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Oddly shaped rock formation, misassociated with a nearby utopian community.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.