Woodbane (Stronghold Augmentation)

Woodbane: When creating this augmentation, choose one face of the wall. No wooden objects can come within 10 feet of the chosen side of the wall. Fixed wooden objects with a circumference greater than 3 inches—such as most trees—are unaffected. When creating the augmentation, you can choose to include the first 10 feet above a wall of stronghold space in the augmentation (for instance, to protect your wall-mounted guards from arrows).
You cannot apply this augmentation to walls of wood or living wood.
Caster Level: 11th; Prerequisites: Craft Wondrous Item, repulsion; Market Price: 33,000 gp.