 In 1920, Rahnsdorf was merged into the city of Berlin as a consequence of the "Greater Berlin Act" and from 1949 to 1990 it was part of East Berlin.Located in the south-eastern suburb of Berlin, Rahnsdorf is the easternmost locality of the city.The easternmost point is represented by Springeberg, a ground located in front of Flakensee lake, bordering with Woltersdorf and Erkner, two municipalities of the Oder-Spree district, Brandenburg.