We stayed overnight here in Haderslev on the way up to Sweden. It was a grey and cloudy day. But we needed a bit of a walk - especially our dog.
So we headed to this little beach. It's not wide, but has a good length. Besides some seaweed it is a very clean place with only very few visitors that day. But we enjoyed the quiet time here in the late afternoon. I believe on sunny day it will be busy, but also on this cloudy day it did have its own charm. There are some (free) parking lots along the main road and a Beach Bar further east.
If you're in the area, it's sure worth a visit.