Pyongyang Castle is one of the National Treasures of North Korea. The castle was attacked by Geunchogo of Baekje in 375. In 427, Jangsu of Goguryeo transferred the Goguryeo capital from Gungnae Fortress (present-day Ji'an on the China-North Korea border) to Pyongyang Castle, a more suitable region to grow into a burgeoning metropolitan capital, which led Goguryeo to achieve a high level of cultural and economic prosperity.