Kyakhta or Kiakhta (both: kyäkhˈtə) [key], city, Buryat Republic, S Siberian Russia, near the Russian-Mongolian border. Kyakhta is on the highway from Ulan-Ude to Ulaanbaatar and is a major transit point for Russian-Mongolian trade. It has textile, lumber, and food-processing plants. Founded in 1728, it was a trading point between Russia and China; it was then a trading center between Russia and Outer Mongolia. Until 1935 it was called Troitskosavsk.