The Brittlestone Parapets

From the introduction: Three miles of ragged, magic-torn trench span Brittlestone Pass. Such is the detritus of wizards. A generation ago the lich Guilmonte ruled the pass and charged toll to all who passed his crooked yellow tower. His practice offended Boolino the Arcane, a wizard of great power and greater ego. The sorcerers and their minions battled, necromancy against academic thaumaturgy, to exhaustion or destruction. The land they fought over is now a warped, dangerous scar that lures treasure hunters seeking strange magics and wealth abandoned in the fight.