Anti-Magic Zone
From AmtWiki
Description from the Dor Un Avathar
All forms of magical energy cease to function within this zone, denoted by yellow ribbon placed around the area. Elementals and Summoned Monsters who enter this area are instantly dispelled, as are all enchantments. spells and magical abilities may not be cast and Relics do not work while within the boundaries of an Anti-Magic Zone. These areas may not be dispelled, but are otherwise like the spell of the same name.