I recommend Wonju Kim Chang-dong ENT Clinic.

Kim Chang-dong ENT Clinic has been around for a long time, so it's a popular destination for seniors. They have a specialist on staff. I've been suffering from a cold this winter, so I've been to a lot of hospitals, and finally decided to visit them. I was impressed with their friendly, quick, and accurate diagnosis. They also provided detailed explanations, which was a bit inconvenient. There's no parking lot connected to the clinic, which was a bit inconvenient.