This article deals with Bayerburg Castle, built by the Teutonic Order on the banks of the River Nemunas in historical Žemaitija, and mentioned in 1337–1344. Supported by the Emperor Louis IV (the Bavarian), the Crusaders planned Bayerburg to be the capital of conquered Lithuania. Although their plans were never fulfilled, the construction of the castle and the immediate attack on it were significant events in the Medieval history of Lithuania. The aim of this article is to relocalise Bayerburg Castle. In seeking to determine where the castle was actually built, the author re-examines the Chronicle of Wigand of Marburg and other written sources referring to Bayerburg. He discusses the hypothesis put forward in 2004–2005 that this Teutonic castle should be localised at Plokščiai hill-fort (in the Šakiai district), and re-evaluates the arguments that led to the refutation of the previous interpretation, according to which Bayerburg was at Veliuona (in the Jurbarkas district). The article concludes that the Plokšiai hypothesis is poorly substantiated, and the previous idea that Bayerburg should be localised at Veliuona must be ‘reinstated’.