Kaesong will likely be part of most of the tours
It used to be accesible from Seoul as well as it was one of two areas that you could have day trips to, I guess that may explain its reasonably high visit count.
I was very keen to visit when I was there, but found out that tours had been suspended
. Hey ho, I had to make do with my 3 minutes on North Korean soil at the DMZ instead, so it doesn't really count as a country visit for me.