A retired military stronghold on the rolling green coast of Donegal.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

The house where the writer spent his formative years.

A stunning Victorian abbey and walled garden on a lakefront.

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

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

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

Andrew Carnegie funded the building of almost 3,000 libraries across the world, this was the first.

This was once a hall in which a 16th-century royal banquet was hosted by King James VI of Scotland.

This charming old building's loose connection with the Scottish Reformer is what saved it from demolition after it split apart.

This volcanic plug boasts the longest recorded history of any Scottish stronghold.

The heart of a Scottish legend had a centuries-long journey before reaching its final resting place.

A castle in the Scottish Highlands has been continuously inhabited since the 1300s.

One man spent 10 years building a spectacular section of road because no one else would.

This Scottish manor house is a lush relic from the life of a literary great.

A giant pineapple, a symbol of hospitality, and an amazing vacation rental option.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

Considered one of the most haunted places in Europe, this 800-year-old castle was home to noble prisoners.

This private residence was the template for one of the most beloved television homes of all time.

Beautiful Victorian buildings from L.A.'s forgotten architectural past.

A historic fort commemorating the United States' naval history.

The famous animator's private station house and man-cave was the birthplace of imagineering.

This grand mansion has starred in everything from Bones to Buffy.

This glamorous old building is said to have inspired the Tower of Terror.