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

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

The world's toughest modern Christian pilgrimage leads directly to the gates of Hell.

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

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

Once the longest bridge in Ireland, this rusting span sits abandoned and overrun by nature.

66,000 pieces of art, donated by one of the world's richest men.

An island filled with hundreds of hanging, decomposing, decapitated dolls.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

The remains of this deep, dark mine have left behind a haunting rocky warren of tunnels.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

A moody and picturesque riverside ruin overgrown with vegetation.

At this cozy bar tucked down a hidden Galway backroad, Guinness makes the Gaelic come out.

A corkscrew-shaped barn in Ireland.

Obelisks and stone pineapples in the Irish countryside.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

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

One of Ireland's most infamous prisons for rebels including men, women and children.

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

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

A thin pane of glass keeps visitors from sliding off this futuristic skywalk.