Ipseokdae, standing 950 m above sea level, is located southwest from the summit of Mudeungsan. Not only is it regarded as an important geological heritage, it is also the representative cliff with colonnades of Mudeungsan. Widely known for its massive size and beauty, Ipseokdae is one of most popular tourist attractions of Mudeungsan. Ipseokdae is a rocky cliff with colonnades in a north-northwest direction. The cliff consists of 40 columns which are 120 m wide and 20 m high. The face widths range from approximately 0.6 to 1.2 m and the diameter of the columns is less than 1.5 m. Ipseokdae is composed of Mudeungsan tuff. Later, the formation was intruded by microscopic granite. The colonnades of Ipseokdae, once believed to have formed of lava, are actually formed of pyroclastic layers of the inner caldera. About 10 m high slanted joints, called Seungcheonam, is found at the top of Ipseokdae. Nam-seon Choi, one of the most prominent poet of late Joseon period, interpreted the origin of the word, Ipseokdae, as “the translation of standing stone” and mentioned that standing stone was an important symbol in ancient civilizations. Meanwhile, the name for Seungcheonam derieved from a legend in which a monk hid a goral that was being chased by a big snake called Imoogi.