Don't wear shorts, jeans or sandals when visiting Panmunjeom as you will be barred from entering. "Unkempt or shaggy hair" is also forbidden so tie it up or cover it. And when you are at Freedom Pavilion, don't wave at, point to or attempt to communicate in any way with North Korean border guards. Generally it’s preferred that smart casual dress is worn in all areas where respect should be shown, such as the above or Buddhist temples etc.