Wander among the abandoned ruins of this once-powerful medieval town.

The ruins of a medieval monastery named after a type of tree.

A tribute to the incredible generosity the Choctaw Nation showed the Irish people during the Great Famine.

This ancient Irish landscape boasts hundreds of legendary ruins.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

The house where the writer spent his formative years.

There might not be much left of these Irish ruins, but their linguistic legacy is still going strong.

A nun spent 16 years painting the stunning Celtic mural that covers the interior of this WWI memorial.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Stripes of human ashes cover a back lawn in the most sought-after burial grounds in Paris.

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

Ordinary art transforms to extraordinary thanks to locals' quirky sense of humor.

This Parisian gem is one of the most incredible ethnographic museums in the world.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

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

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

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

A surrealist timepiece by the artist of melting clocks.

Paris' linguistic guide to the international language of, yes, love.

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