Folklore and circumstantial evidence seem to suggest that stave churches were built upon old indigenous Norse worship sites, the hof. Dietrichson believed that the stave churches were closely connected to the hof and the "hof theory" attracted interest in the 1930–1940s. The theory assumed that the hofs were buildings with a square and a raised roof supported by four columns. During Christianization of Norway local chiefs were forced to either dismantle the hofs or to convert hofs into churches. Bugge and Norberg-Schultz accordingly claimed that "there is no reason to believe that the last hofs and the first churches had any major differences" ("og da er det liten grunn til å tro at de siste hov har skilt seg synderlig fra de første kirker"). This assumption has been rejected by archeological evidence several times, in the case of Iceland by Åge Roussel. Olaf Olsen described the hof merely as function related to ordinary buildings on major farms. If the hof was a particular building they remain to be identified, according to Olsen. Olsen rejected the hof theory. Nicolay Nicolaysen also concluded that there is not a single case known of a hof that was converted to a church.