Reddit reviews Finn MacCoul and His Fearless Wife: A Giant of a Tale from Ireland

Ah, cool - it is a fascinating place. I'd estimate it stretches somewhere between one to two miles of coastline but most people use the bus instead of walking and so only see a tiny portion of it - there are some key bits of interest like the organ and the Giant's Boot.
Also don't forget it's counterpart in Scotland - Fingal's Cave which lead to the story about Finn MacCool - there are lots of versions but this is the ones that I love reading to my children and is the closest to the one my wife was told as a child.