The secret city built by the Manhattan Project.

This replica of the Greek structure is in the heart of Nashville.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

Enormous lake at the bottom of a unique cave system.

This center tells the story of one of the most famous battles in Irish history.

A gated cross stands on the site where an Irish revolutionary met his end.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

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

The world's only flying boat museum honors a small Irish village that sent 20th-century aviation to new heights.

A strange egg in a mucky bog of western Ireland marks the spot of an aviation milestone.

Modern sundial uses ancient methods to tell time and date perfectly.

The severed head of a 17th-century Irish martyr lies within an intricate golden shrine.

The house where the writer spent his formative years.

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

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

A steam trawler with a whiskey-soaked history driven ashore in 1960 resides rusty but still standing on the shoreline.

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 world's tallest box hedge is found in a delightful garden.

A stunning Victorian abbey and walled garden on a lakefront.

The home of Ireland's last leprechauns is officially protected by the European Union.

Traveling this mountain pass reveals quaint stone buildings, stunning Irish scenery, and a bridge said to grant wishes.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

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