As mentioned above, another brilliant story about witches with a fabulous location is [[A Witch in Winter by Ruth Warburton]]. That's one of the other books which has kept me awake in the early hours of Monday morning, as are [[Poison Heart by S B Hayes]] and [[Choker by Elizabeth Woods]].
Hollow Pike is a cauldron of bitchiness, menace and crow-ridden trees, all written in one of the most convincing teen girl voices that I've read for some time. I met James Dawson at YALC recently and he told me it was easy to write like this because "inside I'm a sixteen-year-old teenage girl". (Said whilst rocking the Daenerys Stormborn look, complete with "modesty dragon"!)