It's nice to see a fellow barbarian fan. Castle is my favorite theme, and I've put some time into trying to recreate some barbarian scenes, characters, and structures. Check out some of my creations and the stories that I've written about my medieval world on my page. Once again, cool set.
Quoting Brett ost (Bread)
how did you make the curved wall
Lots of 1x1 round bricks and 1x2s. Alternate between them (1x1, 1x2, 1x1, 1x2) and stagger each level one stud to the side. All of the 1x1s should line up on the diagonal. You can see it in the tree shots.