Alan Garner. The Weirdstone of Brisingamen (1960); and The Moon of Gomrath (1963).
I have just finished reading aloud the two earliest Alan Garner books, which is always a good test. I first encountered them in my mid teens, Gomrath first, caught fishing in the village library shelves - therefore read them initially in reverse order.
I can still recall (sitting on my tree platform retreat! - book in hand) an almost delirious excitement at finding a book featuring two children encountering the world of magic surviving (hidden) into modern times, and containing Tolkien-like dwarves and a wizard, and convincing but strange elves.
Garner adds his own distinctive elements, in the very detailed setting of both stories is his birthplace and home Alderley Edge in Cheshire; and an element of British folklore which is blended with the fantasy.
The folklore element comes partly from his own local knowledge, but also substantially from the 'neo-pagan' revival including the methods and stance of Robert Graves The White Goddess.
Garner has indeed remained within this neo-pagan world view ever since - dropping the fantasy and focusing more on the folklore. Consequently, the metaphysical basis of these books (and his others) is in reaction-against Christianity - but not reacting into secularism, but into the past as perceived through a neo-pagan lens as a place of where life was real, enchanted and deep (and with Christianity implicitly regarded as working against this enchantment and depth).
The Moon of Gomrath (specifically) contains some really thrilling and memorable writing - the passage where Colin sees The Old Straight Track revealed by the rising full moon is wonderful; and indeed whenever the subject matter is The Old Magic (that is, nature magic as contrasted with the learned High Magic of wizardry) the writing is exhilarating. And this applies to the very last sentence - it is rare and unusual for a book to end so well.
(In fact Garner has said that he often works back from the last sentence, which comes to him by inspiration).
My conclusion is that my teenage evaluations were about right: Gomrath is an outstanding work, Weirdstone much less so - being rather dull in some stretches, in particular the sixty something pages (about a fifth of the book) in underground tunnels.
(I think the dullness comes mostly from Garner having inserted too much literal detail from results of his geographical researches into the Alderley Edge terrain, including explorations of its mining remnants.)
Nonetheless, both are well worth reading, and the Weirdstone has several memorable parts, including in the otherwise overlong underground sequence.
The pursuit across the plains below Alderley Edge is very evocative - and the 'baddies' are well realized: the svart-alfar (i.e. dark elves - i.e. goblins), and the terrifying Mara are (unfortunately!) unforgettable.
Garner went on to write Elidor, which was a step down in quality, and had something about it I didn't like - probably the typically mid-sixties Leftist theme of brooding class consciousness and resentments.
Garner was born into the artisan class but became upper middle class via an elite education - the famous Manchester Grammar School and Magdalen College, Oxford. The tension of this transition, and the subsequent attempt psychologically to undo it, are obsessively dwelt upon throughout his later work.
These class conscious elements also featured at the core of The Owl Service, which was pure folklore without fantasy elements; but were triumphantly swept up into a near perfect novel of mounting fear and tension, resolved at the very last with a triumphant twist and elation when Garner brilliantly transcends his own prejudices.
After The Owl Service came Red Shift which is almost incomprehensible - being almost entirely in pared-down dialogue and without explanation (Owl Service was sometimes on this path, but avoided excess) - and from that point Garner disappeared into - or underneath - a self-consciously 'crafted', pretentious but constipated prose with less and less of substance (or goodness) to make it worth digging-through the overlying inspissated matter.
In sum, Garner's writing career demonstrates both the special strength and ultimate weakness of the neo-pagan reaction. In the Weirdstone and Gomrath he was briefly able to re-enchant modern life by presenting it as a thin skin concealing ancient folklore and behind that magic.
But (I infer) the anti-Christian motivation led him inexorably on to brooding on his own class resentments which were so trite, so dull - and indeed so ultimately wicked, that their clichéd nature needed deliberately to be disguised behind ever more experimental and less accessible writing.
All that aside - if you like Tolkien, do read The Moon of Gomrath at least - and probably Weirdstone too.