Was there years ago for a conference & had a half day to faff around. There a nice walk to the castle with lovely views of the city & Danube.
I also managed a visit to the national gallery & natural history museum- both were within walking distance of the old town
At that time it wasn't (as yet) infested with hens & stags but was heading that way. Beer wise all I was looking for was Pilsner Urquell- not everywhere had it- lots of places it's just Zlaty Bazant