Zmievskaya Balka, Zmiyovskaya Balka is a site in Rostov-on-Don, Russia at which 27,000 Jews and Soviet civilians were massacred in 1942 to 1943 by the SS Einsatzgruppe D during the Holocaust in Russia. It is considered to be the largest single mass murder site of Jews on Russian territory during the Second World War. The name means "the ravine of the snakes".