In the "Introduction" to Moonrunner, some of the player's heroic exploits are listed, among them "defying the monstrous Vampire Lords of Vannan". Although the locations of Vannan is not given, it seems likely that it is somewhere in the Old World. Given the association of Vampires with Mauristatia, and the proximity of that land to Blackhaven, where Moonrunner largely takes place, it seems not unlikely that Vannan is somewhere in Mauristatia.