This building is hard to describe in English but basically it is a cultural center that was built for the benefit of the workers in Hrastnik. Various cultural activities and events are offered here, from movie nights to kids' theatre plays to exhibitions of art and handicrafts. Many of these events are free and the few exceptions have a modest entry fee. The organization that operates this center is called the KRC and has an office at nearby Log 3.
I think municipal cultural centers like this are a really great idea. They support the creative work of local residents. In America it often felt like art was a luxury item that only rich people could afford. Here, culture is treated as a necessity and it is given good support from the local government, and everyone can participate. That's the way it should be.