
Originally Posted by
Pharoh Amon Khan III

Originally Posted by
jammi567
Another unanswered question is: why are the towns blocked during disk four?
Because you're out of sync with their time.
If that were the explanation, you should not be leave Ultimecia's castle at all, because you're just as "out of synch" with the whole rest of the world map.
The barriers are probably just something Ultimecia put up to stop all attacks while she was compressing time.