The Hyrcanian Forests World Heritage property is situated in Azerbaijan and Iran, within the Caspian Hyrcanian mixed forests ecoregion. It stretches approximately one thousand kilometres along the southern and south-western coast of the Caspian Sea and covers around 7% of the remaining Hyrcanian forests in Iran. Most of the ecological characteristics of the Caspian Hyrcanian mixed forests are represented in the property. Its component parts contain 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. The floristic biodiversity of the Hyrcanian region is remarkable at the global level with over 3,200 vascular plants documented.