This, along with At The Mountains of Madness, are my Lovecraft favourites.
During my "dark period" I bought several of his books and it never ceased to impress me how he came up with his own "chantic" to summon Cthulhu. I'm sure it is a lot easier to do it these days now that we have Lord of the Rings and all these made-up languages but, back in H. P Lovecraft's days, I am sure no one would ever think of something of the like.
I am not into the fantastic world anymore, but this remains one of my favourites. I'm still trying to figure out why...