In reply to Tim Chappell:
The Old Town is interesting in a bombed out and completely rebuilt kind of way; there was a particularly magnificent band of old codgers there banging out a few numbers, who were a cross between the Stones and the Wurzels. Absolute gold - I hope they are still going but they must be at least 150 by now!
The various memorials to the Holocaust in the ghetto are worth a sombre visit, and the ridge of high ground to the east above the river where most of the adult male population were wiped out similarly. There's not much 'original' authentic pre-war Warsaw left, but plenty of dismal Cold War concrete apartments and the giant concrete "Wedding Cake' palace of Culture and Science looms above the lot.
Lazienski Palace was probably the best of the old palaces IIRC, but it was a decade or more since I was there.
Have a great trip
b