I don’t many of those on this RSPB Community Forum have heard of this RSPB reserve outside of Norfolk called Sutton Fen which was bought by the RSPB in 2007. There is practically no visiting allowed to this RSPB reserve, except very occasionally guided walks. Below an article from The Guardian in January 2007 about Sutton Fen a few months after Sutton Fen was bought by the RSPB and the reason why practically no visiting is allowed at Sutton Fen and last I found this short video showing Sutton Fen of which as far as I know there are very few videos about Sutton Fen
https://www.theguardian.com/environment/2007/jan/08/conservationandendangeredspecies.uknews
https://youtu.be/JCwcRpJZcXY?si=4ZNEHtNUEM-jBPGvv
Regards,
Ian.