Thanks for the explanation Rossim. And Parnassus must be good though I don't understand why but it gets me a good answer for another blank which I'm going to keep quiet about as it's so obvious it's embarrassing!
Accept us - Pass Us
holding a service A RN (A royal navy)
the height (mountain) of poetry.
Mount Parnassus - home of the Greek muses?? (or something similar, i think)