This tree is very solid and sturdy.  The openings are tight for my 22 pound cat, but he manages to get through them.  He is too big for the hammock and it is a little tight turning around on some of the smaller platforms.  Nevertheless, he loves it and has hardly come down since we got it!  It took about an hour for two of us to put it together.  I would give it 5 stars if the openings were a little bigger.  I spent a lot of time researching and looking for cat tree for a large cat.  This would be better for my big boy is the openings were wider.