Idar-Oberstein is a town in the Birkenfeld district in Rhineland-Palatinate, Germany. As a Große kreisangehörige Stadt, it assumes some of the responsibilities that for smaller municipalities in the district are assumed by the district administration. Today's town of Idar-Oberstein is the product of two rounds of administrative reform, one in 1933 and the other in 1969, which saw many municipalities amalgamated into one. The various Stadtteile have, however, retained their original identities, which, aside from the somewhat more urban character encountered in Idar and Oberstein, tend to hark back to each centre's history as a rural village. Idar-Oberstein is known as a gemstone town, and also as a garrison town. It is also the largest town in the Hunsrück.

Rio Grande do Sul is a state in the southern region of Brazil. It is the fifth-most populous state and the ninth-largest by area. Located in the southernmost part of the country, Rio Grande do Sul is bordered clockwise by Santa Catarina to the north and northeast, the Atlantic Ocean to the east, the Uruguayan departments of Rocha, Treinta y Tres, Cerro Largo, Rivera, and Artigas to the south and southwest, and the Argentine provinces of Corrientes and Misiones to the west and northwest. The capital and largest city is Porto Alegre. The state has the highest life expectancy in Brazil, and the crime rate is relatively low compared to the Brazilian national average. Despite the high standard of living, unemployment is still high in the state, as of 2017. The state has 5.4% of the Brazilian population and is responsible for 6.6% of the Brazilian GDP.