The Welsh have their "leeks", Den.
In "Borstal Boy", Brendan (Dominic's brother, of course) has the line about Scotland:

"God help the poor Scotchmen, they'll never be free,
But we're entirely surrounded by water"

On a very old-fashioned RTE Radio One programme, "Failte Isteach" ("Welcome in"), Donncha O' Dulainn regularly plays a recording of this one; it's on on Saturday nights at 10pm. I say "old-fashioned"; to judge by the Requests and Dedications, there must be hundreds of Irish nuns scattered in convents all over England and America.