Ralsko () is a town in Česká Lípa District in the Liberec Region of the Czech Republic. It has about 2,100 inhabitants. It comprises area of the former military training area with Hradčany Air Base. Because of the former military area, the town's municipal territory is the fourth largest in the country, after the cities of Prague, Brno and Ostrava. Administrative parts The town is made up of town parts and villages of Boreček, Horní Krupá, Hradčany, Hvězdov, Jabloneček, Kuřívody, Náhlov, Ploužnice and Svébořice. The municipal office is located in Kuřívody. Geography Ralsko is located about southeast of Česká Lípa and southwest of Liberec. It lies in the Ralsko Uplands. The town is named after the mountain Ralsko, which lies on the northern municipal border and is the highest point of Ralsko and of the entire Ralsko Uplands with an altitude of . The Ploučnice River shortly crosses the municipal territory in the northeast. There are several ponds in the area, the largest of them are Hradčanský and Novodvorský. History The oldest part of Ralsko is Kuřívody. The first written mention of Kuřívody is from 1279, it was founded between 1264 and 1278 by Ottokar II of Bohemia as a royal town. Due to lack of water, it remained a small town throughout its existence. Before 1945, there was more than 7,000 inhabitants in today's Ralsko area. At the beginning of 1945, Hradčany Air Base was built by German army. After the World War II, the German majority was expelled. In 1950, the Ralsko military training area was established. In 1992, it was abolished and the municipality of Ralsko was established. In 2006, Ralsko became a town. Ralsko military training area Between 1946 and 1950, the inhabitants were relocated to establish a military training area in surroundings of the Ralsko mountain. The displacement of the population was completed on 31 October 1952. More than 3,000 inhabitants were evicted from the villages. The Ralsko Mountain and the airfield were used as a military weapons-testing area for decades. After the Prague Spring of 1968, the installation was manned by Soviet Troops. In the late 1980s the Soviet 442nd Missile Brigade stationed SS-21 short-range tactical missiles at Hvězdov. It 1988, there was more than 20,000 permanent Soviet inhabitants (soldiers and their families) in the area. After the collapse of the Soviet Union in 1990–91 the missiles were withdrawn and the entire weapons-testing area