He was assisted in this by Karl Maria Wiligut, an occultist who was popular in German ultra-nationalist circles. Himmler brought Wiligut into the SS—where he eventually rose to the rank of Brigadeführer—and gave him a private villa in Berlin. Using Wiligut's prophecies as his guide, Himmler selected Wewelsburg castle in Westphalia to serve as a base for many SS operations. The architect Hermann Bartels was employed to oversee renovations to the castle to make it fit for the SS's use. As part of these alterations, one of the rooms in the building became known as "the Grail Room" with a rock crystal representing the Holy Grail being placed in a central position. Himmler also established a private museum at the castle, employing the young archaeologist Wilhelm Jordan to manage it. In 1934, Himmler met the Dutch prehistorian Herman Wirth, who was then living in Germany, at the home of Johann von Leer, a Nazi propagandist. Wirth was one of the most controversial prehistorians in Germany. After examining symbols found in rural Frisian folk art, he became convinced that they represented the survival of an ancient script used by a prehistoric Nordic civilisation. This script—Wirth believed—was the world's oldest written language and had been the basis for all other ancient scripts. He also believed that if he could decipher it then he would learn the nature of the ancient religion of the Aryan race. This belief conflicted with established scholarly understandings of the past; by the 1930s, scholars were aware that the world's two oldest scripts were those of Mesopotamia and Egypt, and that northern Europe only developed its own form of literacy, that of the runes, under the influence of Etruscan script between 400 BCE to 50 CE. Attempting to explain the lack of any archaeological or historical evidence for an ancient advanced Nordic civilisation, Wirth claimed that the Aryans had evolved in an Arctic homeland two million years ago, before establishing their advanced society on a land in the North Atlantic which had since sunken into the sea, giving rise to the stories about Atlantis. Wirth's ideas were rejected and ridiculed by the German archaeological establishment, although they had gained the support of several wealthy backers, which assisted him in promoting them. Himmler was among those who liked Wirth's ideas. Himmler was interested in the pre-Christian religions of northern Europe, believing that a modern Pagan religion modelled on them could replace Christianity as the primary religion of the German people.