My mum's maiden name is Denn and my cousin has traced our ancestry. Mum's paternal side, the Denn's, were from Denn parish and were traced back to the 1700s. At some point they went to Liverpool but not sure when as my cousin has all the detail. Be interesting to know if there are still any Denn families in Cavan.
Hello,
In the 1911 census of Ireland, there were 72 people named Denn. None of them were in Cavan. To determine whether there are Denns in Cavan now, perhaps use the Irish white pages online.