I agree with you Tony - it does look like he did the building first, but I disagree about the rock island thing.
picture shows one similar to one in one of the lakes near where I grew up. one side was totally dominated by this big bald rock, and the other side was overgrown with ferns and trees. It was only out a little ways in the lake, and we used to swim out there and jump off the rock.
Back on topic
The only thing I dont like about this moc is it's too bright. I think he should have used sand green to tone it down a bit. He has a nice dark house, black roof, spooky cave, and bright green foliage. Just doesn't work for me.
HOWEVER - that criticism aside. this is a great moc, and very nicely done. I always love looking at this guys stuff, and really wish he were a member here. I'd like to pick his brain on some of these.