On the other hand, one objection to the Odysseus Unbound theory is that (whether or not subsequent landslips could have converted it into the current landform) the hypothesized channel was an implausible geographical structure. It is not clear what natural processes could have created a deep valley linking two arms of the same sea which was several miles long yet only a hundred yards or so wide at sea-level throughout. (If it existed today, it would be a world-famous natural phenomenon.)