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

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

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

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

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

While only two of the ancient buildings at this site are actually churches this was one of the earliest Irish pilgrimage sites ever.

A nun spent 16 years painting the stunning Celtic mural that covers the interior of this WWI memorial.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

A corkscrew-shaped barn in Ireland.

A sacred well steeped in Pagan roots on the West Coast of Ireland.

An ancient neolithic tomb that only sees the sun twice a year.

A moody and picturesque riverside ruin overgrown with vegetation.

A remarkably intact castle that once was the largest in Ireland.

Obelisks and stone pineapples in the Irish countryside.

The oldest inn in Kilkenny was established by the first convicted witch in Ireland.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

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

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

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

Local legend says the remains of Father Christmas lie within the medieval grounds.

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

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.