Not very far from the town of Louisburgh stands a very pleasant mountain called Croagh Patrick. It is about two thousand five hundred and ten feet in height. It was on that mountain that St Patrick spent forty nights and forty days in prayer to God. It was off Croagh Patrick that St Patrick was supposed to banish the serpents and to drive them out of Ireland. It is said that when St. Patrick banished the serpents from Croagh they fled into Lough Derg in Donegal and it is said the water of that lake has a brown colour ever since and that is why it is called "Loch Dearg".