As part of the Unified Community Platform project, your wiki will be migrated to the new platform in the next few weeks. Read more here.
The Great Bulwarks can be found in the mountains near Grim Batol. They are series of interlocking peaks with an incredibly high metal ore content. The ley line pattern of this area makes them utterly impassable - all things, from lava flows to storms to travelers must pass around the Great Bulwarks, for they cannot pass through or over them. It is from this ley line pattern that the Shielding Pattern is derived.