Sketchbook Tower

This is another lesson, the 6th, from David Williams' book on drawing. I bought it after I found his candle & flame tutorial online. 

I'm not all that happy with the way the rocks turned out but I do like the tower itself. Not bad for a first try... will try it again in a couple of weeks to see the difference...

Strathmore Recycled Sketch Paper, fine tooth surface, WindpowerⓇ
5.5 x 8.5" 60 lb paper with cretacolor pencils