Ruyan (Persian: رویان), later known as Rustamdar (رستمدار), was the name of a mountainous district that encompassed the western part of Tabaristan/Mazandaran, a region on the Caspian coast of northern Iran.
Ruyan (Persian: رویان), later known as Rustamdar (رستمدار), was the name of a mountainous district that encompassed the western part of Tabaristan/Mazandaran, a region on the Caspian coast of northern Iran. (en)