Biraeam is a monolith located on a top of Mansandong valley. It is 650m above sea level, about 100m tall and 500m wide and stands like a huge folding screen. Rising alone in the surrounding hills, it became a landmark in the area in terms of its peculiar size, shape, and location. The name Biraeam is from legend that a rock flew from Mt. Geumgangsan and landed on the site. The Biraeam’s mineral texture is of dense and tough quartz porphyry. About 100 million years ago, granitic magma which erupted from 100-350km below the earth intruded into older metasedimentary rocks and hardened. Later, the host rock surrounding the intrusion got eroded away and only quartz porphyry remained.