It's good to see a server remake which is attempting something new and purposeful (and it does look visually impressive so far), rather than just digging up something which already died of natural causes, or trying to achieve easy success by piecing together other peoples work and pushing it on a new platform.
It does however seem that at least some of the tiles might have been blown up from LTTP:
Classic's sewer dungeon walls were based on the same thing, and especially with Graal itself originally being a rip of and even still containing tiles from Zelda, I know it's easy to get that impression when it might not be the case. Making the comparisons, it does seem like those forest temple tiles are just a couple of pixels different from the blown up Misery Mire tiles.