I visited the Carolingian Westwork and Civitas Corvey in the summer of 2018 when I drove from Belgium to Berlin.

I visited the site on my own without a guided tour. There wasn't a whole lot available in English and I couldn't tell if there were any English language tours or guidebooks available. 

The interpretative tools available for non-German speakers was rather slim. It was one of the least accessible sites I had visited in all of Germany (and I have visited most of the German sites). 

I spent about 2 hours exploring the grounds and taking photos. At least the entrance fee was affordable. 

This site is probably only going to be of interest to local school groups and world heritage site completists.