Rivne Oblast (Рі́вненська о́бласть), also referred to as Rivnenshchyna (Рі́вненщина), is an oblast (province) in western Ukraine. Its administrative center is Rivne. The surface area of the region is . Its population is: Before its annexation by the Soviet Union during World War II, the region was part of the Second Polish Republic's Wołyń Voivodeship following the Polish–Soviet War. Previously it was part of the Volhynian Governorate. The Rivne Nuclear Power Plant is located in the oblast, near the city of Varash. Volhynia The region is located almost in the middle of the historical region of Volhynia which is indicated on its coat of arms with a white cross on a red background. Volhynia was completely partitioned after the Soviet occupation of Poland in September 1939 and divided between three oblasts, Volyn, Rivne, and Ternopil, with some additional eastern portions in Zhytomyr Oblast. The relief of the region varies, its northern portion lies in the Polesian Lowland, while its southern is located within Volhynian Upland. The highest hills known as Povcha Upland reach over 350 meters. The main water artery of the region is river Horyn, while northwestern area also reaches Prypiat. Big portions of the oblast covered in woodlands. It also has a great deal of such excavated minerals like amber and basalt. In recent years (2016–2017) there were reports of illegal extraction of so called Rovno amber in the area. File:Rivne oblast detail map.png|Detailed map of Rivne Oblast File:Rivne_Oblast_2020_subdivisions.jpg|Subdivisions of Rivne Oblast Administrative divisions of Rivne Oblast On 19 July 2020, the number of districts was reduced to four. These are: Dubno (Дубенський район), the center is in the town of Dubno; Rivne (Рівненський район), the center is in the city of Rivne; Sarny (Сарненський район), the center is in the town of Sarny; Varash (Вараський район), the center is in the town of Varash.