Warsaw isn't exactly a 'must see', but I think most places have their merits and almost anything beats time in a soulless Airport Hotel.

It's a very modern city with numerous high-rise buildings. The reasons for that are quite fascinating, with the Nazi plan to pretty much wipe it off the face of the Earth under the Pabst Plan, WW2 fighting, uprisings, Soviet invasion etc. On the basis of that horror I can't really criticize it for not being as pretty as say, Krakow, with the Old Town pretty much entirely a modern reconstruction using old paintings etc. as reference points.

The Market Square, Castle Square, King Zygmunt's Column & the Barbican are all in close proximity and tick a lot of the tourist boxes during a pleasant & easy stroll around.

I thought the Warsaw Uprising Museum and nearby remnants of the Jewish Ghetto walls were interesting, time permitting.

This being a watch forum, a visit to the top of Stalin's monstrous Palace of Culture & Science - until quite recently the World's tallest clock tower - is well worth it for the ear-popping elevator ride and incredible roof-top views.