The Taw yağı (pronounced [tʌʊ jʌˈɣɯ] in Tatar) or Viryal (Tatar: Тау ягы, romanized: Taw yağı; Chuvash: Вирьял; Russian: Го́рная сторона́, literally Hill Bank Land) was a historical region of Tatarstan, Khanate of Kazan, Volga Bulgaria, the name is known since the 1550s.
The Feudal lords of the Hill Bank Land eventually joined Russia following 1556.
The region had multiethnic population (Russian: горные люди) and included Tatars, Chuvashes, Hill Mari and Mordvins.
During the Russian Civil War, White guerrillas were based in the forests here.
The hills themselves became recently known for their dachas, resorts and Alpine skiing.