Fortress architecture
Goguryeo, the largest kingdom among the Three Kingdoms of Korea, is renowned for its mountain fortresses built horizontally and vertically along the incline of slopes. One of the well-preserved Goguryeo fortresses is Baekam fortress (白巖城) constructed before 6th century in present-day South-West Manchuria. A Chinese historian noted, "The Goguryeo people like to build their palaces well." Patterned tiles and ornate bracket systems were already in use in many palaces in Pyongyang, the capital, and other town-fortresses in what now is Manchuria.