A controversial gift from Stalin is called the Palace of Culture and Science (Palac Kultury i Nauki, PKiN). For most (but not all) Poles, including me, this building is a symbol of communism and Soviet domination over Poland. I remember very well these sad and grey times of no freedom, of poverty, persecutions, humilations and first of all of no hope for better future except immigration or... quiet psychiatric ward in the nearest hospital. It's not so old past. Although, I can understand foreign visitors amazed with that, indeed, unusual structure in Warsaw and even telling me that it was the best what they had seen in Warsaw.
There are hundreds jokes on the Palace. Well, good laugh was the best way for active/creative people to survive communism without any mental disorders. The abbrevation PKiN is similar to Polish name of Chinese capital - Pekin (Beijing), which is a symbol of neither freedom nor democracy. So, the building is sometimes called Pekin. It's sometimes called "Pajac" (Puppet) as well (Polish "pajac" is similar to "palac" = palace).
Many people want to hide that "shame" for Warsaw and support building a lot of (90 as for now) skyscrapers around: look here. Once Polish FBI investigated the case of some Polish stupid young jokers searching for terrorists who would agree to blow the palace up.
The best idea is to set up large and modern Museum of Communism (Socland). The idea is supported, among many others, by Andrzej Wajda, the famous Polish film director. As for now lack of political decision, not money delays the idea of Socland. Some left-wing Polish politicians still wrongly confuse Russia and the former Soviet Union and are afraid of irritating "the White Bear" = Russian rulers. Their idea of neither disclosing nor publicizing true about communism gives some support from some Western European political figures. Is it European freedom?
A big mistake can be to think that this is Polish architecture! It's a gift of Staline (communism), and many Poles don't like it! Staline has killed so many Poles!.......So take a picture of it, but don't tell Poles that it's the most fabulous building that you have seen and that they can be proud of it ;) Ok?