@Gibbonsagainstgravity Yes this enclosure still exists. I believe that it was built over 100 years ago and over 100 baboons have been kept in it at once apparently (not sure how many these days). Its better than some other classic baboon rocks like Frankfurt but it is cramped and outdated in my opinion.
Having never visited Cologne, this enclosure looks really good to me. Plenty of height from the rocks, decent amount of space, and good climbing asides from the rocks. Its hardly in the same league as, say, Zurich, but compare it to the enclosures at Hagenbeck or Colchester and it really doesn't seem that bad. However, from what I have heard, overpopulation and inbreeding are serious issues, so perhaps there are greater issues than a picture can demonstrate, that someone more familiar with Cologne could inform me on.
EDIT: I tried to link to the media on ZooChat, but instead it just opened the photo, so credits to twilighter, snowleopard and MagpieGoose.