Hi Wojtek,
Before you go to either of the places you have written about you better have a look at the sites cited here (or some others, there is plenty of information in the net) and decide, what you would like to see. I mean, 1-2 days are not enough to see much.
If you select some particular objects, we will gladly provide information and advice. You can also find people who would go with you if you like of course.
Good luck!