Gonghu(공후): Harp used in ancient times in Korea

What a beautiful sound!!! The instrument in this video is called Gonghu(공후), which is a harp used in the ancient times in Korea. It is said to have been originated from a Chinese instrument, Konghou.
Do you know about 공무도하가(公無渡河歌), the oldest surviving song in Korea? Many people say a Korean woman played the Gonghu while singing the song. I think Gonghu is so suitable for that kind of sad songs...
ok... Let's just enjoy this beautiful sound of Gonghu!