I just finished a week of training and teaching at Grapping Krakow. It is a very nice school that has every day two grappling trainings. Classes are splitted up between student levels and go/no-gi.
The most interesting part for me, was the fact that they have a lot of tall (read as people with long legs) higher belts and it was frustrating to see how short my arms really are. Furthermore, many of these guys are good with De La Riva and even berimbolo sweeps... something I considered only useful for small fighters... well... guess not. (although they change the way they apply it a bit)
Anyway, nice atmosphere... go train there when you are in the neighborhood.