Hyrcanian Forests is a serial site with 15 components stretching 850 km along the southern shore of the Caspian Sea and the northern slopes of the Alborz Mountain. It is a remarkable series of sites conserving crucial ecosystems of the Hyrcanian Region and contains exceptional broad-leaved forests with a history dating back 25 - 50 million years ago, when such forests covered most parts of the Northern Temperate region. These huge ancient forest areas retreated during Quaternary glaciations and later, during milder climate periods, expanded again from these refugia. The World Heritage site covers most environmental features and ecological values of the Hyrcanian Region and represents the most important and key environmental processes illustrating the genesis of those forests, including succession, evolution, and speciation (IUCN, 2019; World Heritage Committee, 2019).