Ida-Viru County County in the NE of Estonia(pop. 137,000). is the most northeastern part of the country (population approx. 137,000). It borders with Lääne-Viru County County in the north of Estonia (pop. 60,000). to the east, Jõgeva County County in the eastern part of Estonia (pop.29,000). to the southwest and Russia to the east. The main mineral mined in Estonia, oil shale, is mined in Ida-Viru County County in the NE of Estonia(pop. 137,000). . The Kohtla-Järve oil shale museum is in the county.