Feuerberg DGC is likely the most beautiful and entertaining course I've played on so far. It's located above the village of Feuerbach in the bucolic landscape of the southern Black Forest where the foothills of the Hochblauen peter out into the Rhine valley with the Swiss alps and Vosges towering towards the horizon. The course slopes around vineyards and cherry orchards, through old woods and up and down the Triassic hills that encompass Feuerbach.
It has been designed and is being maintained and constantly improved by just one guy in his spare time, so don't expect anything overly polished; Some of the baskets are still hand-made, but are being replaced one by one with new Viking Royal baskets. All tees have tee mats except those where you tee off from the road/concrete.
The currently 27 holes total are being grouped in several layouts that hold every bit of challenge and provide an awesome mix of discgolf experiences in the most gorgeous scenery. In-forest tunnel shots, uphill climbs, wood traverses with different routes to chose from, narrow fairways and wide open prairie drives are all here for your entertainment.
If a hole can momentarily not be played due to either cows on pasture, farmwork in an orchard or high grass, Sebastian has a pool of replacement holes he can set up so you will always be able to play a full round.
For me, the biggest thrill came with the constant elevation changes: on some holes you need to be just a little bit off on your angle and your drive will sail down in the valley, so shot selection really is key.
You can refill your water bottles at a drinking trough on the course and (depending on the season) might find snacks like apples, walnuts, cherrys and prunes in this rich environment.

Note: None of these is really a con to me, just things you have to consider if you get to play here.
First of all, even though this is mainly on public land, it is a private course & invite only, so you should get in contact with Sebastian first. He lives with his family right by the course, is super friendly and chances are he's going to offer to show you around - a treat not to be underestimated. While there are tee signs, it's still tough to navigate and you won't know where the OBs are and get easily lost by yourself. Also, it saves a bunch of time and is a lot more fun playing with a local.
Second, this course is a challenge and also quite a hike (so nothing to play a quick round with kids or beginners on, though I believe Sebastian has a shorter layout for such). I recommend hiking boots and you should bring ample time and snacks to fully enjoy. We played an 18 hole tournament layout the Freiburg DG Club had staged their "League day" on earlier and it took us 3 hours (even with locals and despite skipping the last couple holes). I believe I still have seen less than 50% of the total course area!
Also, you will spend quite some time searching for discs. I was not used to those kind of elevation changes and was completely off on distance perception when looking for my drives (even on open pastures). It helps playing with numerous people who can spot & help put your perception into perspective (for instance if you go deep OB on #1 and find yourself in a mind-boggling cherry orchard with each row looking exactly the same).
Lastly, though this is a year round course, I imagine it being quite slippery in winter on some of the slopes and high grass on the pastures could be an issue in summer. Spring and Fall are the best times to play here with nature's beauty being on full display.

To me, this is true destination discgolf, located in one of Germany's prettiest regions. There's nothing like sending a drive into this most epic of backdrops and with the course being as vast and challenging as it is you can spend a week here playing it every day and still discover new things (something I'm planning for my next trip).
If you want to check it out and are looking for accommodation in the area, I can recommend the high end bed-and-breakfast "Am Paradies" in Feldberg, otherwise the "Ochsen" or "Landhotel Graf" in Obereggenen are also both fine. All are within 40 min hiking distance of the course (10min by car).