'Fenced cities' definitions:

Definition of 'Fenced cities'

Fenced cities There were in Palestine (1) cities, (2) unwalled villages, and (3) villages with castles or towers (1 Chr. 27:25). Cities, so called, had walls, and were thus fenced. The fortifications consisted of one or two walls, on which were towers or parapets at regular intervals (2 Chr. 32:5; Jer. 31:38). Around ancient Jerusalem were three walls, on one of which were ninety towers, on the second fourteen, and on the third sixty. The tower of Hananeel, near the north-east corner of the city wall, is frequently referred to (Neh. 3:1; 12:39; Zech. 14:10). The gateways of such cities were also fortified (Neh. 2:8; 3:3, 6; Judg. 16:2, 3; 1 Sam. 23:7).
The Hebrews found many fenced cities when they entered the Promised Land (Num. 13:28; 32:17, 34-42; Josh. 11:12, 13; Judg. 1:27-33), and we may estimate the strength of some of these cities from the fact that they were long held in possession by the Canaanites. The Jebusites, e.g., were enabled to hold possession of Jerusalem till the time of David (2 Sam. 5:6, 7; 1 Chr. 11:5).
Several of the kings of Israel and Judah distinguished themselves as fortifiers or "builders" of cities.