Did you know that, despite being on the north side of the Liffey (where the odd numbered post-codes live), the Phoenix Park is actually in Dublin 8? And it's not for the reason you might think. Thus spoke Wikipedia:
"There is a very simple, practical reason why the Phoenix Park is in Dublin 8 and it has nothing whatever to do with snobbery but with practicality.
Long before there were postal codes the James's St Postal Sorting Office looked after the Phoenix Park because it was considered to be closer and more convenient than Phibsborough (Dublin 7). James's St continued in this role when the postal codes were introduced so Dublin 8 it had to be."
This interesting fact courtesy of a 20-minute argument in Morelli's chipper on Thomas Street that almost ended in a fist-fight.