Wewelsburg (German pronunciation: [ˈveːvəlsˌbʊɐ̯k]) is a Renaissance castle located in the village of Wewelsburg, which is a district of the town of Büren, Westphalia, in the Landkreis of Paderborn in the northeast of North Rhine-Westphalia, Germany. The castle has a triangular layout - three round towers connected by massive walls. After 1934, it was used by the SS under Heinrich Himmler and was to be expanded into a complex acting as the central SS cult-site.