You can see three Irish counties from this Neolithic hillside fort, once the seat of the Kingdom of Ailech.

An autonomous republic of Orthodox monks.

Rodin's famous depiction of Dante's 'Inferno', amidst a sculpture garden of many of his other works.

The ancient tomb acts as a calendar that keeps perfect time.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

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

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

An abandoned Byzantine fortress and notorious prison.

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

This legendary city has been a tourist attraction for centuries.

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

The site of the first medieval crusade that pitted Christians against Christians.

This enormous "cloth of the conquest" depicts the Norman invasion of England in mind-blowing detail.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

French commune at the heart of conspiracies.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

Historic medieval fortified city in southwest France.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

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

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

One man's remarkable private collection of art from around the world.