Ayu-Dag (Crimean Tatar: Ayuv Dağ, Ukrainian: Аю-Даг, Russian: Аю-Даг, Greek: Αγια (Aya - "Holy"^[1])) is a summit of Crimea. It is also known under the Russified name Medved'-gora (Bear mountain) (Ukrainian: Ведмідь-гора, Russian: Медведь-гора). The summit is located 16 km north-east from Yalta between the towns of Gurzuf and Partenit.

Its Ancient Greek name was Κριοῦ μέτωπον (Kriou Metopon), meaning Ram's Head.^[2] The Slavic language variants of the mountain's name are translations from the Crimean Tatar name and mean Bear Mountain ("bear"- ведмідь in Ukrainian, медведь in Russian, ayuv in Crimean Tatar; "mountain"-гора in Ukrainian and Russian, dağ in Crimean Tatar).

The mountain is a laccolith. Today its territory is a Nature reserve (5.5 km²). There is a pioneer children's camp Artek near Ayu-Dag which is well known internationally. The eastern slopes of Ayu-Dag lead to an ancient settlement Partenit.

Remains of an early-medieval settlement and a number of churches were discovered here. In the 9th-10th centuries it was a well-known seaport, bound with cities of the Byzantine Empire. The western slopes lead to Artek.