I have had this question since I learned about there to be (which was a long time ago), and I know there used to be means something that used to exist, i.e, it no longer exists, for instance: There used to be a house across my apartment = One house used to exist, but no longer does, it's something that existed in the past, but not anymore. So, based on the facts that were mentioned, every there to be has a negative form and interrogative, therefore, what's there used to be's ?
My question has been identified as a possible duplicate of another one, but the one suggered isn't the same as mine, I'm talking about the verb there to be, the other question is about the verb "used to", both questions are different from each other.