They may be grammatically correct (correct me if I'm wrong), but they sound so awkward that you might as well count it incorrect. I'd say they're not correct because noone use it that way. You want to specify what and where approximately 'this place' is in your sentence.
For example, "Is there this place called Blah's bleh in London?" "Nope, I've never heard of it. Is that a bar or something?"
Please feel free to add to or correct my post.
Student or Learner