The main Korean mountain range (“Baekdudaegan”, BDDG) is thought to have served as a major glacial refugium for plants. Phylogeographic and palaeoecological studies support the hypothesis of the BDDG as a plant refugium. The BDDG merits high priority for conservation also because of its floristic and cultural value. Cooperation between the two Koreas is needed to guarantee the preservation of the BDDG.