I found many, so called, "Sessions" in County Clare Ireland. And in central Dublin a bit of a con. two or three musicians (that were obviously getting paid for it), to create an atmosphere. It didn't work for me. If you tried to join in they frowned at you. Best ones were at Howth (Barny Mckenna's) the Lighthouse. Or the National folk music center in Monkstown.

Chas