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

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

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

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

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

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

The oldest public library in Ireland.

A moody and picturesque riverside ruin overgrown with vegetation.

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

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

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

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

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.

Obelisks and stone pineapples in the Irish countryside.

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

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

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

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

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

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.

The world of the ancient Celtic civilization explained through a bewitching 11 acre garden.