COEX Mall, containing COnvention centers, EXhibition halls and many malls, is an underground shopping mall in Gangnam-gu Seoul, South Korea. It has an area of about 154,000 square metres, of which 144,000 square meters are on a single underground floor, making it the world's largest underground shopping mall. The mall is located at Samseong-dong served by Samseong Station on Seoul Metro Line 2, at the intersection of Teheranno and Yeongdong Dae-ro.