'Locks' in the Bible

And of Beth-horon the higher and the lower, walled towns with walls and doorways and locks;

He said to Judah, Let us make these towns, building walls round them with towers and doors and locks. The land is still ours, because we have been true to the Lord our God; we have been true to him and he has given us rest on every side. So they went on building and all went well for them.