ana, the building with swimming pool under castle rock is national historical monument (narodna pamiatka, neviem ako sa to povie po anglicky :), it's functionalistic swimming pool build in 1920's or 30's. impossible to get imho ...

notoricky znama budova s kupolou will be part of "new danube waterfront". they'll keep it and rebuild and make fancy restaurants and cafes etc in it (as far as i know)

btw what about stara ikea? i think it still belongs to ikea, it's guarded but maybe they would like the idea of using the building (ie. try it the official way)