confine

An area or region that's confined can only be reached by one way, like a dead-end street.

The word "confine" is often used to talk about limits and boundaries. Imagine you're at a music festival with a big map of the grounds. If there are certain areas where people can't go, like backstage or behind fences, those places are confined within the rest of the event space. It's like setting rules for a game: we confine ourselves to the playing field so everyone knows what they can and can't do.