COEX Convention & Exhibition Center is a convention and exhibition center located in Samseong-dong, Gangnam District, Seoul, South Korea. COEX is serviced by Samseong station on line 2 and Bongeunsa station on line 9 of the Seoul Subway. The 836-meter section of sidewalk along Yeongdong Boulevard from exit No. 5 of Samseong station on to exit …COEX Convention & Exhibition Center is a convention and exhibition center located in Samseong-dong, Gangnam District, Seoul, South Korea. COEX is serviced by Samseong station on line 2 and Bongeunsa station on line 9 of the Seoul Subway. The 836-meter section of sidewalk along Yeongdong Boulevard from exit No. 5 of Samseong station on to exit No. 7 of Bongeunsa Station is designated as a smoke-free zone by the Seoul Metropolitan Government.