Today,I went Chang-deok palace.Don-hua mun is the oldest and biggest gate between 5palaces gate.In second floor,there are bell and drum.If bell rang 33times,it means person can go out or come in the Seoul.Or,if bell rang 28times,people can't go out or come in.In-jeong-jyon is the  main structure in  Chang-deok palce.In there,king work there.