Rock of Ages

Well, perhaps the title is a little misleading. It has nothing to do with the hymn of the same name. Rather, this is an ages rock. It sits on the harbour side in Arklow and nobody ever pays any attention to it. Except the photographers. I am not a geologist but I know there are some out there in Blipland. Anybody know what sort of rock it might be? My guess, from limited knowledge and from the fact that it is obviously a soft stone, would be limestone.