Like all walls it was ambiguous, two-faced. What was inside it and what was outside it depended upon which side of it you were on. Looked at from one side, the wall enclosed a barren sixty-acre field called the Port of Anarres. [...] It was in fact a quarantine. The wall shut in not only the landing field but also the ships that came down out of space, and the men that came on the ships, and the worlds they came from, and the rest of the universe. It enclosed the universe, leaving Anarres outside, free. Looked at from the other side, the wall enclosed Anarres: the whole planet was inside it, a great prison camp, cut off from other worlds and other men, in quarantine.

Chapter 1 (pp. 1–2) - Hainish Cycle - The Dispossessed (1974)