There are some really interesting design features such as the silver tinted windows, giving a beautiful reflection of the bright sun, but also keeping the building cool.
It takes 3-4 months to clean all the windows with track lines, a series of ropes and for the spire: men hand cleaning! Just like in Vietnam really.
What's even more shocking is that there may be an even taller construction in Saudi Arabia, adding just over 100m and breaking world records. It seems like the sky simply isn't the limit.
Here's a link for more information:
I don't think there's any building in Hanoi as amazing as this one!