Yes there are. 
I’m not good at planning and neither at partying … Irish Pub sounds good, though, the Jameson Pub looks very nice from the pictures.
Another thing:
There is one of Europe’s biggest open-air museums in the surroundings of Köln. You get there with the train, but should allow for some time, since you need at least two hours to walk around and have a quick look, more if you want to look a bit closer 
It’s not entirely medieval, but there are houses built in 16th century, so it will be certainly interesting.
Web Page Open Air Museum
A short description in english
I will go there either Thursday or Saturday. If anyone is there and has some time to spend outside of the gamescom, I would be very glad to have some company 
I also would like to pay a visit to this beautiful Renaissance castle:





. And even on Friday evening I’m gonna visit the backer event of Star Citizen, so I think I’m out of this. But have fun and some beers, guys!
maybe, see you