Seoul Lantern Festival Held annually since 2009, the Seoul Lantern Festival is again taking place across Gwanghwamun Square and just to the south of it at Cheonggye Plaza and Seoul Plaza. The lights come on from 6 p.m. to 10 p.m. every day through Jan. 21. Also open at the same time is the Gwanghwamun Square Market, potentially the largest winter flea market in the capital. Seasonal goods including crafts and stree...