DSC_5377 by earl_of_design, on Flickr
The steel is really taking shape now.
I was surprised by that too. I would have thought a square core would be much easier to make, but who knows with today's construction technology, maybe it's no different.It's interesting that the concrete core is curved like the facade. I'd have though it would have been rectangular. I wonder if the elevator lobbies will also be curved. That would be a nice touch.