I didn't discover this, but when I found out about it I had to go check it out for myself. Apparently there is a building, where if you climb up the side of it, it appears to show a reflection of the twin towers.
Is it? Isn't it? I don't know. All I know is that if you look behind you where the reflection WOULD be coming from, there are no large buildings there at all. Now where this is located is NOT where the twin towers would have stood, which leads some people to say thats its not really a reflection, but rather if you were looking "through" the building towards where the towers would have been. Because if you climb to the top and look south you can see where they would have stood. Other people just say its just a glitch in the reflections. But the reflections on all the other buildings in this game are so fantastic and on point that I find this being a "glitch" a little hard to believe. Either way, its a pretty cool little thing in the game.