... when the Pevensie children had returned to Narnia last time for their second visit, it was (for the Narnians) as if King Arthur came back to Britain, as some people say he will. And I say the sooner the better.

From The Voyage of the Dawn Treader

In addition to Fenris Ulf, the old American versions of LWW include a reference to Yggdrasil, the World Ash Tree fundamental to Norse mythology's concept of the universe.

The more recent version replace this with the more-general "fire-stones on the Secret Hill".

Paul Ford, in the footnotes for the World Ash Tree entry in his Companion to Narnia, comments that, in his opinion, the vagueness of the druidic (fire-stones) is preferable, because the Norse is so very specific.

Interesting, I have the older American versions of LWW but I don't remember a reference to the world tree.

You could also look at the White Witch as kind of Medusa-like with the whole turning people to stone thing.

The quote comes in chapter 13, "Deep Magic from the Dawn of Time," in which the Witch says,

Tell you what is written on that very Table of Stone which stands beside us? Tell you what is written in letters deep as a spear is long on the trunk of the World Ash Tree? Tell you what is engraved on the sceptre of the Emperor-Beyond-The-Sea?...

Another, slightly different take on mythology in the Chronicles is explored in Michael Ward's Planet Narnia, which looks at medieval cosmology and seeks to tie each of the books to a specific planet and its accompanying symbolism.

I haven't read the book yet but a couple of threads discussing it are available on the old NarniaWeb here and here.

The VODT can be considered an 'immram', a type of medieval Irish tale where the protagonist goes on a voyage to the Otherworld but stops at fantastic islands along the way. The one's preserved since ancient times all start with "The Voyage of.."
And Reepicheep's little boat (coracle) is the traditional boat used by the Celts.