As an antonymical thread to the one on major cities with multiple routes connecting them, what are some examples of (preferably large but many people, myself included, ignored that bit for the other thread) settlements which are only connected by one route?
Ideally I'd be looking for pairs with only one route between them, no diversions at any point, and far enough apart and large enough that having multiple routes is a realistic expectation (so e.g. I'm not looking for Sheffield to Barnsley).
I'm sure there's going to be lots, but a shorter list than the other thread; Exeter to Plymouth's the first one which comes to mind, with London to Chelmsford and Colchester, if not further north, needing large enough diversions if not going via the Great Eastern Main Line that I'd count those as well.
Ideally I'd be looking for pairs with only one route between them, no diversions at any point, and far enough apart and large enough that having multiple routes is a realistic expectation (so e.g. I'm not looking for Sheffield to Barnsley).
I'm sure there's going to be lots, but a shorter list than the other thread; Exeter to Plymouth's the first one which comes to mind, with London to Chelmsford and Colchester, if not further north, needing large enough diversions if not going via the Great Eastern Main Line that I'd count those as well.