Pics are good, generally, but the light is very flat and boring, except in No.2 which is wonderful.
You did really well to get down low, giving an awe-inspiring perspective, with better light. The shadow at the very front is a bit distracting (was someone standing in your light?), and you just about clipped the top of the castle off. Try giving it more space, or cropping it tighter.
Cool stuff though. How long did that take to build?