According to Wikipedia, Jongmyo Shrine is a Confucian shrine dedicated to the memorial services for the deceased kings and queens of the Korean Joseon Dynasty. The site is said to the oldest royal Confucian shrine preserved in all of Korea. It has been on the UNESCO World Heritage list since 1995.
Gyeongbokgung Palace was originally constructed during the same year, 1394 by by King Taejo, the first king and founder of the Joseon Dynasty.
Both Jongmyo Shrine and Gyeongbokgung Palace have been heavily damaged by Japanese occupation but as of 2009, have been restored much to their original state.