I think this odd drinking cup comes from either Newcastle or Sunderland, though Sunderland Lustre was made elseware. It isn't marked so it's difficult to tell.
It's odd because the base is so thin it should fall over when filled with water but it doesn't. It's impossible to tip it over without pushing it with great force. It might be cracked, not sure, it might just be crasing. Anyway, it was only 50p.
It's my first piece of Sunderland Lustre and I'm not surprised that it's really collectable as it's stunning.