Egyptian cities had walls, even larger private residences and temples would be walled to protect against robbers or bandits. The largest cities, like Memphis and Thebes had no walls until quite late, but they didn't need any. They were surrounded by developed areas and troops, so bandits and stuff weren't a problem, and they were well in the interior of a highly-developed state with few external threats--compare this to Rome, which was unwalled for most of antiquity because there was no need for walls whatsoever. Archaeologically, villages and towns quite frequently show walling or signs of ramparts