Seats traditionally used as part of ancestor worship on display in the National Folk Museum of Korea (국립민속박물관), in Gyeongbokgung Palace (경복궁), Seoul (서울).
Food and drink would be offered to ancestors at these special seats as part of ancestor veneration ceremonies. It was thought that the spirits of ancestors would protect and look after the living.
Please note the above description is from memory, and apart from the location, may be totally wrong.
Straightened in CNX 2