Korean nationalist historiography is connected with popular archaeology in South Korea, where television archaeologists competing for ratings make ever more-expansive claims to the limits of ancient Korea. For example, in 1993 the Korea Daily sponsored a trip of archaeologist Son Bo-gi of Yonsei University to Ulan Bator, Mongolia where Son claimed that he discovered a new Goguryeo stone fortress which proved that Goguryeo extended beyond the Greater Khingan range. Korean Bronze Age art has been connected by popular archaeologists, for example, to that of the Scythians, supposedly proving the arrival of a superior northern race into the Korean peninsula. Korean journalists and researchers also regularly travel along Silk Road sites in Central Asia searching for Korea's Altaic roots. Choe Nam-seon, writing in the territorial tradition of Shin Chae-ho, argued that Korea was the center of the Purham culture which extended deep into Central Asia. According to Choe, the world was divided into Indo-European, Chinese, and Părk cultures (Purham munhwa kwŏn), the last of whom was a Korean Shinto-like religion that spread from the Black Sea through the Caspian Sea, Tian Shan, the Altai Mountains, down through Korea, Japan, and Okinawa. Choe alleged that Dangun was universally worshiped within this super-culture. However, according to Chizuko Allen, Choe did not examine the local cultures of any countries besides Korea, China, and Japan, and based this theory on phonetic similarities of geographical features. Choe's Purham culture theory has since been adopted by the independence activist and Korean Studies movement leader An Chae-hong.