If you haven't seen this exhibit at the MET yet - it's ahhhmmmaazzzinng and definitely worth checking out. Created by Tomas Saraceno, Cloud City is a modular installation that is housed on the 5th floor of the MET on the roof garden and is composed of honeycomb like structures grouped together in a non-linear formation. The exhibit is open until November 4, 2012 and you can find the information on hours of operation here.
While you are permitted to roam inside the exhibit, you need a ticket (free of charge) which is on a first come first serve basis. Unfortunately when I went they were out of available time slots so I had to admire the exhibit from the ground - which is still pretty remarkable.
The intricacy of the exhibit is stellar - with reflective material and mirrors plating various facets of each of the modules. Certain panels are left open which let see through the exhibit and every angle looks similar but incredibly different at the same time. It has architectural roots with an abstract feel that's just amazingly cool.
If you end up taking pictures - just be careful if you take some while facing up. We had an unfortunate accident which ended in a shattered phone screen so make sure you hold on tight to your cameras/phones while snapping away!