Tickets for the annual spring nighttime tours of Changdeokgung will go on sale at 4 p.m., Thursday. On Thursday through Sunday from April 11 to June 2, six tours will take place per day -- three starting a little past 7 p.m. with another three starting around 8 p.m. The guided tours will start at Donhwamun, the palace’s main gate, making stops at the various halls and residential quarters -- including Injeongje...