On a small island in the middle of an Irish lake called Lough Derg, there is a gateway to hell. Before anyone panics, there is already a monastery over the portal called St. Patrick’s Purgatory.

The story goes that Jesus showed St. Patrick a cave on Station Island (sometimes described as a “pit” or “well”, of which there are a few shallow ones remaining), in which the saint received visions of the punishments of hell, and was subsequently able to use the site as proof of a Christian afterlife for his wavering followers. Actual history does not confirm whether the saint truly visited the island or if it was simply associated with him later, but the monastic compound constructed on the island exists to this day. Much expanded from its founding in the 15th century, some of the foundation still remains, and the bare stone style of the existing priory buildings recalls the site’s ascetic Christian roots.

While casual visitors are not generally allowed on the island, yearly pilgrimage to the site continues to this day where devout worshippers come in droves to take a three-day sojourn of contemplation through the holy site, all while barefoot. The local Lough Derg website even touts the pilgrimage as “the toughest in all of Europe, perhaps even in the whole Christian world,” thus keeping the “purgatory” in St. Patrick’s Purgatory.