The course is located on the campus of the Idraetshojskolen Sønderborg (IHS), a private folk school focusing on sports education. It sits on the eastern edge of Sønderborg next to a wonderful remote beach with a wooden pier and close to the Marina (where you can find public restrooms and can moor your boat overnight or camp for a small fee and use the showers).
The course is on private (school) property and there are "no trespassing" signs, despite the area being wide open. We just went anyway and asked 2 girls working there who we found to be very friendly and welcoming (they even showed us the first tee). During weekdays, you might want to contact the school in advance, contact info can be found here: https://www.ihs.dk/?lang=en (Danish and English) or in the course info.
The course terrain is sloped towards the beach, so it provides some elevation changes and several groups of nice old trees, while being somewhat guarded from the wind by the surrounding woods. The baskets are old Mach 3 but they still catch well.
Once you located the tees, the course allows for quick play and is (mostly) beginner friendly.
If you forgot to bring your discs, you can pick up a Latitude starter set @ føtex supermarket in downtown Sønderborg.

The biggest con for me is navigation, especially the absence of proper tees or any signage at all. I've found 3 kinds of tee markings: yellow tiles, specks of concrete slab & a marble windrose embedded in the lawn. None of these are to spot from more than 5 feet away and as there is no course map you really have to search for these. As further encumbrance, there are no tee signs, so the normal course of action once you find something is A) is this a tee? B) if it is one, what hole does it belong to?
As a rule of thumb it might help that #1 tee is at the building next to the volleyball courts (which are OB) and from there on you move roughly clockwise around the premise with #5 and #6 being at the far end (behind the soccer field).
We played on a weekend and had the place pretty much to ourselves, but I can see it getting busy during campus hours with all sorts of outdoor activities (volleyball, zip lines etc.) coming into play.
Lastly, the distancing seems to be a little off. #1 and #6 are too short (you could just move #1 tee 50ft back, otherwise a putter will do) and seem geared towards beginners, but then #5 comes as a 518 ft low ceiling par 3...

It wouldn't take much to make this awesome: first of all, add some tee signs! Even a simple wooden pole would be a great improvement, as you could spot it from some distance. Also, a course map with official distances & par information would make this more accessible to newer players (who otherwise would be completely lost).

In its current state, it is still worth checking out as Sønderborg is a cool city and the course area is nice but most of all: where else can you jump in the ocean and sit on a beach right after your round?