The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically been considered as a natural barrier between Eastern Europe and Western Asia. Mount Elbrus in Russia, Europe's highest mountain, is situated in the Western Caucasus. On the southern side, the Lesser Caucasus includes the Javakheti Plateau and the Armenian highlands, part of which is in Turkey. The Caucasus is divided into the North Caucasus and South Caucasus, although the Western Caucasus also exists as a distinct geographic space within the North Caucasus. The Greater Caucasus mountain range in the north is mostly shared by Russia and Georgia as well as the northernmost parts of Azerbaijan. The Lesser Caucasus mountain range in the south is occupied by several independent states, mostly by Armenia, Azerbaijan, and Georgia, but also extending to parts of northeastern Turkey, northern Iran and the self-proclaimed Republic of Artsakh. The region is known for its linguistic diversity: aside from Indo-European and Turkic languages, the Kartvelian, Northwest Caucasian, and Northeast Caucasian language families are indigenous to the area. Origin of the name Pliny the Elder's Natural History (77–79 AD) derives the name of the Caucasus from a Scythian name, Croucasis, which supposedly means 'shimmering with snow'. German linguist Paul Kretschmer notes that the Latvian word kruvesis also means 'ice' (actually 'frozen mud'). In the Tale of Past Years (1113 AD), it is stated that Old East Slavic Кавкасийскыѣ горы (Kavkasijskyě gory) came from Ancient Greek Καύκασος (Kaúkasos), which, according to M. A. Yuyukin, is a compound word that can be interpreted as the 'mountain of the seagull(s)' (καύ-: καύαξ, καύηξ, -ηκος, κήξ, κηϋξ 'a kind of seagull' + the reconstructed *κάσος 'mountain' or 'rock' richly attested both in place and personal names). In Georgian tradition, the term Caucasus is derived from Caucas ( Ḳavḳasosi), the son of the Biblical Togarmah and legendary forefather of Nakh peoples. According to German philologists Otto Schrader and Alfons A. Nehring, the Ancient Greek word Καύκασος (Kaukasos) is connected to Gothic hauhs 'high' as well as Lithuanian kaũkas 'hillock' and kaukarà 'hill, top'. British linguist Adrian Room claims that *kau- also means 'mountain' in Pelasgian, though this is speculative given that Pelasgian is so poorly known. Toponyms The term Caucasus is not only used for the mountains