Bishop of Wrexham Peter Brignall (pictured above, centre) has announced plans to shut 22 out of 62 churches in the area by 2020 in a move he admits some people may find "shocking".
The closures will affect towns and villages including Abersoch, Cemaes Bay, Conwy, Criccieth, Hawarden, Llanberis, Morfa Nefyn and Saltney.
Writing in an open letter, Bishop Peter Brignall, said: "To some it will be shocking, to others not radical enough; to some it will come as a relief, to others a disappointment or even a scandal; to us all it will be a challenge, but I firmly believe also a huge opportunity for renewal.
"It will mean pastors and communities will have to look afresh at how we live parish life, how the Catholic Church in North Wales is profoundly missionary.
"There will need to be parish meetings and decisions made about names of new parishes, cooperation about new Mass times, support of your priests as they come to terms with new arrangements; and brother priests and deacons support of your people as they understandably grieve over what is lost.
"For all though, this is both a time of remembering and thanksgiving for those from whom we have received the faith, their endeavours and their sacrifices.
"In each of the churches that are to close, I will celebrate a final Mass of thanksgiving for all our benefactors in faith and goods."
In contrast, Bishop Brignall also unveiled plans for new churches in Connah's Quay and in Broughton.