On the ground of the 'Monastery Clonmacnoise' stands the Cathedral Temple McDermot. The north doorway often called the "Whispering Arch", dating to the mid-15th century.
This ornate Gothic doorway dating to the fifteenth century is apparently a popular spot for wedding proposals. Folklore has it that the doorway once had a very unusual use: Lepers would stand at one side of the doorway and whisper their sins into the half pipe in the architrave. The priest would stand at the other side of the arch, far enough away to avoid infection, listening to the confession emerging from the architrave.
The cathedral is the largest of the churches at Clonmacnoise. Rory O'Connor, the last High King of Ireland, was buried near the altar in 1198, joining his father Turlough. Most of the graves currently seen in the church are those of the Coghlan family, whose patriarch extensively rebuilt the cathedral in the mid-seventeenth century.