I recommend Dongtan Seongmo ENT Clinic in Yeongcheon-dong, Hwaseong-si.

This is the hospital my wife and I go to every day. Haha

There is a downside to this, which is that you have to wait more than an hour every time you go. But it's a hospital that everyone in the neighborhood knows about. Haha

My wife, who suffers from colds, allergies, and rhinitis, goes there quite often. Haha.

If you live nearby, you should definitely go.