Have you looked at a site near to the middle of the Black Forest named Alisehof at Bad Rippoldsau-Schapbach. It is a 5 star site where we have stopped 5 times and enjoy very much. From there you can visit anywhere in the Black Forest easily. We have been there every year in recent years and my reviews of it are in our trips taken in Europe over the last 8 years on my website as in the link in my signature. There are two other sites we have been to mentioned which are quite good but not as good as Alisehof. Owners Herr and Frau Bonath are lovely people, welcome you and are most helpful. The toilets, showers etc., are excellent too. It is in a rural, pretty position but shopping is nearby in the old town of Wolfach. On arrival you will be given a Black Forest Card for free travel on local transport and discount for various attractions. If there is any more information you would like please contact me. This is an ACSI Camping Card site if you are going out of season.
I did look for the site you mention above but could not find it I personally have never seen it mentioned before.
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