Kiachta, or Kiakhta. a. Russian town on the Chinese frontier, in the province of Transbaikalia, 165 miles S.E. of Irkutsk. The Chinese town of Maimatchin is in the immediate neighbourhood. From the Treaty of Nertchinsk in 1689 to that of Peking in 1860, by which Russian vessels were admitted to Chinese ports, Kiachta was the chief centre for the exchange of Russian and Chinese goods. The former are chiefly manufactured goods and furs, the latter silks, nankeens, porcelain, and, above all, tea.