For many centuries, the Silk Road crossed east to west through the Irano-Anatolian Biodiversity Hotspot, connecting the Mediterranean Basin and Western Asia. The hotspot includes major parts of central and eastern Turkey, a small portion of southern Georgia, the Nahçevan Province of Azerbaijan, much of Armenia, northeastern Iraq, northern and western Iran, and the Northern Kopet Dagh Range in Turkmenistan.

Nearly 400 plant species are found only along the Anatolian Diagonal, a floristic line that crosses Inner Anatolia; many of Turkey’s 1,200 endemic species occur only to the immediate east or west of it. The hotspot is also home to four endemic and threatened species of viper.