Kohtla-Järve (Russian: Кохтла-Ярве) is a city and municipality in north-eastern Estonia, founded in 1924 and incorporated as a town in 1946. The city is highly industrial, and is both a processor of oil shales and is a large producer of various petroleum products. The city is also very diverse ethnically: it contains people of over 40 ethnic groups Only 21% of the population are ethnic Estonians; most of the rest are Russians.