The EASA is not public in Cologne, although it is in one of the most interesting architectural buildings in Cologne.
But on the day of the open heritage, which is once a year in Germany you can enter it. I made a photo of a cabin door and the inner life of it, but wasn’t allowed to post it, probably because of security reasons.
Have a look here:
https://goo.gl/maps/QQmeW5XwP1kwiHtj8?g_st=ac
I visted so many nice places that day that I hardly had time for photos being in a rush, and I will share the nicest locations with you in the next days.