During the 13th century Prussian Crusade, the current Gvardeysk area was conquered by the Teutonic Knights. To protect Samland from the Nadrovians and Scalovians, the crusaders built a wooden fort between the Deime and Pregel rivers from 1283–90. This was replaced by Tapiau Castle, a stone Ordensburg, in 1351. Vytautas, forthcoming grand duke of Lithuania was baptised here in 1383 after he breached of Krėvė prison. Since 1450 town and castle was named Tapiau. After Teutonic state was downed by Poland and Lithuania, Teutons moved order archives to Tapiau castle and kept it during 1469-1722. Later Tapiau castle was abbandoned. Soviets built a jail on the mound, it remains active.
References:Střekov Castle (Schreckenstein) is perched atop a cliff above the River Elbe, near the city of Ústí nad Labem. It was built in 1316 for John of Luxembourg, the father of the Holy Roman Emperor Charles IV, to guard an important trade route to Germany. After changing hands several times, the castle was acquired by the Lobkowicz family in 1563. Its strategic importance led to occupations by Imperial Habsburg, Saxon, and Swedish forces during the Thirty Years' War, as well as successive sieges by Austrian and Prussian armies during the Seven Years' War.
Although Střekov Castle was heavily damaged during those conflicts and abandoned as a military installation by the end of the 18th century, the 1800s saw many poets and artists visiting the castle, drawn by a new trend of interest in romantic ruins.