From PathfinderWiki

Once a fertile village in central Thuvia, Resa is now little more than a flat stretch of desert with a few scattered signs of civilization.1

During the decline of Osirion's first age, an Usij necromancer named Aryana Tahari took sanctuary beneath the village and used its inhabitants as test subjects in experiments to create a new plague. These experiments eventually lead to the downfall of the village and its citizens.2