Where is China opposite Jeju Island?

Qidong city. According to Baidu map, Jeju Island is located in the southwest of South Korea, facing Lvsi Port in Qidong City, Jiangsu Province across the sea, so Jeju Island in South Korea is opposite Qidong City, Jiangsu Province, China. Jeju Island is the largest island in South Korea, located in the southwest of South Korea, and is a famous tourist island.