  Yes, indeed, there are. At least Leibniz thinks so. In his view, as we saw above, there are an infinite number of possible worlds – worlds that God did not see fit to bring into existence. Now, given that Leibniz's safe claim is that “[t]here are as many possible worlds as there are series of things that can be conceived that do not imply a contradiction,” (Grua 390) it might still be the case that there is only one possible world – only one set of essences that implies no contradiction. If we accept the claim that a possible world is simply any set of compossible individuals (i.e. a set of individuals whose properties or perceptions do not contradict each other), then there is a rather trivial way to show that there are an infinite number of possible worlds. Namely, we just have an infinity of one-object worlds: thus w1 contains a blue, 8lb.  bowling ball; w2, a red, 10lb. bowling ball; w3, a pepperoni pizza; w4, a bicycle; and so on. We could even imagine worlds with two, three, or more objects.