The Simpsons

I am a Chinese person and I have been to the square. It really is just a public square, although security is now pretty intense. You have to buy tickets and your ID is checked before you go in. Not as tight as airport security, but at least as strong as the security check to get into Disneyland.

Regarding the actual incident that the original post is alluding to—most Chinese people are aware that there was a big protest there and that the Government quashed it. Generally, the most common opinion about this is that it was a violent riot that the Government had no choice but to put down, which, if you really dig deep into the history of it and what happened on an hour-to-hour timescale, is not an entirely unfair view of the situation. So when they hear non-Chinese people describe it as a massacre where the Government steamrolled peaceful protestors with tanks, their initial reaction is not anger or bewilderment but one of confusion as to how someone could hold such a strong opinion yet be so uninformed/misinformed.

Discussion about it is not entirely suppressed in China. It's just not controversial and not an interesting topic of discussion for most people.