This picture is a little confusing. Even though the emphasis is on the riverfront and the church, the description talks about the structure on the hill in the upper background.
The description on the back translates as follows:
Wall and towers, floating high above,
The main boldly lifting into the clouds,
Catle Cat looks proud to rich country,
She has to citizen use and profit
Adopted the royal residence here
On vine-wreathed Fensenwald.
— From the epic “Defiance-Cat” by Jörg Ritzel
This is number 129 in the series.