Sorry for the super-late reply ;___; I was working on it during the event, and then lost everything when my mother turned off the computer <.< >.>
Well, we've seen the Chopin's grave at Lafayette Cemetery. I remember the beautiful monument on it, it was really looking amazing ^^ I love those old cemeteries with pretty monuments on almost all graves, like the one in Vienna, where is the grave of Beethoven.
Well, I was in Louvre when I was smaller, so I don't regret it that much. It's too big anyway to see everything at one visit :)
Unfortunately I didn't get a chance to visit Catacombs, but I think it might be really interesting. I also like creepy things and places xD So maybe if I'm back in Paris in future, I will go there.