It is not often that you find a gallery on the 4th floor of a random residential building. But when you do it is always a pleasure. So go to Kralja Petra straight away!
Petar Dobrovic is a Serbian painter who lived and worked during the first half of the XX century. I would not say he is one of the most famous ones, but he is definitely one whose work you should see.
The gallery is actually situated in the apartment in which the artist lived and worked and it has year-long shows in the form of theme-centered exhibitions. At the moment, the theme is his wife Olga. She is on all of the paintings and you can feel how dominant this women was.
The gallery itself is not that big and the only person who was there the last time I went, was a security guard that might not be able to answer all of the question you might have about the work of the artist but he will gladly show you (if you ask him) the booklets and editions about his work that you can buy, and some of them are in English as well.
P.S. The lift in the building is very interesting, so take it when going up but when going down, take a walk and look through the window to the the inner ‘courtyard’.