Walls in Easton's Bible Dictionary

Cities were surrounded by walls, as distinguished from "unwalled villages" (Ezek. 38:11; Lev. 25:29-34). They were made thick and strong (Num. 13:28; Deut. 3:5). Among the Jews walls were built of stone, some of those in the temple being of great size (1 Kings 6:7; 7:9-12; 20:30; Mark 13:1, 2). The term is used metaphorically of security and safety (Isa. 26:1; 60:18; Rev. 21:12-20). (See FENCE -T0001321.)