Very small.  Posts are 1/2 the size of another cat tree that I have.  The carpeting is not really carpet, very thin material.  I have 4 cats; 2 that are 8 pounds, 1 that is 10 pounds and one that is 14 pounds.  Only the 2 smallest can jump inside the cubby.  The biggest won't even attempt to get on the top shelf.  It bobbles when she jumps to the second shelf.  I am afraid if one of them jumps from the top, the entire tree will fall over.  It was on sale for $38 and that's what it was worth.  Wouldn't buy this again.