These moss-covered medieval ruins tower atop the smallest of Ireland's Aran Islands.

This Neolithic passage tomb forms part of a World Heritage Site.

Impressive mining ruins overlook a spectacular view of Ireland's Copper Coast.

After it was swallowed by a Georgian mansion, this medieval castle remained forgotten for centuries.

Behemoth, cannon-like telescope operated by generations of Irish earls.

On the Irish coast, 18 members of the Howard family are eternally resting in an Egyptian pyramid.

This is the largest cemetery in Ireland and the first cemetery museum in the world.

This burial pyramid in central Ireland is thousands of miles and thousands of years away from its Egyptian inspiration.

This modest plaza in Moneygall, Ireland has cashed in on its distant connection to the U.S. president.

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

Ruins battered by centuries of war and disaster offer a wondrous glimpse of medieval Ireland.

These imposing walls and towers look more like the ruins of a fortress than a monastery.

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

This ancient Irish tower could easily have stood in for Rapunzel's prison.

This ancient Irish landscape boasts hundreds of legendary ruins.

Ireland's most remarkable collection of these curious cone-shaped houses is worth the buzz.

This single room has survived the centuries with almost no deterioration.

A stunning Victorian abbey and walled garden on a lakefront.

An 1814 castle that hosts an exhibit of "explorabilia".

The ruins of an 800-year-old monastery boasts the tallest round tower in Ireland.

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

This controversial Irish show cave is home to a massive formation known as the Great Stalactite.

A rocky Irish outcropping with a history of wealth, conflict, and ruin.

A corkscrew-shaped barn in Ireland.