Mudeungsan National Park is a great park that I actually liked a lot. It has a cool community of hikers that are as friendly as they get and a really good variety of hikes.
We were very interested in seeing the two rock formations, Ipseokdae and Seoseokdae. They offer some really cool views of Gwangju but can sometimes be hidden in the haze.
I recommend this for true nature lovers who want to see as many Nature parks as they can. It can also be great if you turn it into a weekend and consider staying in Gwangju or visiting the nearby Boseong Tea Plantations!