Red Banner Town; German: Lasdehnen (1734–1938), Haselberg (1938–1946); Lithuanian: Lazdynai) is a town and the administrative center of Krasnoznamensky District in Kaliningrad Oblast, Russia, located on the Šešupė River, 163 kilometers (101 mi) northeast of Kaliningrad, the administrative center of the oblast, and approximately 10 kilometers (6.2 mi) to the south of the border with Lithuania.

In the early 18th century the town's name was changed to Lasdehnen, based on the Old Prussian language term for hazel bushes, and the current Gothic Revival church was built between 1874 and 1877.

[8] In 1938, during a massive Nazi campaign of renaming of placenames, it was Germanized to Haselberg (literally "hazel mountain") due to the Baltic origins of its prior name.

By 1945, during World War II, Haselberg's ethnic German population had largely fled before the advance of the Red Army in 18 January.

Following the end of the war Haselberg was included in the portion of the former province of East Prussia annexed by the Soviet Union that was organized into Kaliningrad Oblast of the Russian SFSR.