The castle is the former seat of the county (locality) elder (Königliches Landratsamt in German), built in 1897 in the neo-Gothic style. Gothic and red bricks were typical features of public buildings built during that period. Schools, other public institutions had common, characteristic features and formed the visual basis of the architectural landscape of Prussian cities.
The county seat of Seimel (German: Kreishaus) also stood on the castle square, which has now been significantly rebuilt – two floors, with a useful attic – it is a wide, massive building, stylistically different from the old town.
In 1911, a brick house for civil servants (German: Beamtenhäser) was built near the old town. One of them, where the postal workers lived, has been perfectly preserved and until recently was a boarding school for students of technical and basic vocational schools.
During the World War I, the buildings on the castle peninsula together with the so-called Villa Schiborr were handed over to the army. At the turn of 1914 and 1915, from November 16 to February 11, units of the Russian army stayed in the old town building. The headquarters of the 10th Army operated there. After the enemy was driven out of East Prussia, the imperial army was housed in the old town and the adjacent buildings. The headquarters of the 10th German army was located in the village. It was commanded by General Hermann von Eichhorn and Colonel Emil Hellis was the Chief of Staff. General Paul von Hindenburg and Erich Ludendorff visited the troops. Frederick Augustus III, the last king of Saxony, paid his respects with his visit.
During the interwar period, all buildings were restored to their original functions. In 1945, soldiers entered the Castle Square again. This time it was a battalion of sappers that mined the territory of the county from August to December. According to the stories of the first inhabitants of the city, after the change of the statehood of East Prussia, information appeared that the building was used for some time to store looted property of the inhabitants of the city and its surroundings. Later, a training center operated in the town hall building, and from 1951 – a boarding school. In 1959, the surviving buildings on the Castle Square were intended for didactic purposes. The main vocational schools were established in them, and later the headquarters of the complex of vocational schools.