Posted by Blu

A defensive wall is a fortification used to protect a city, town or other settlement from potential aggressors. In ancient to modern times, they were used to enclose settlements.
There are many variations of defensive walls, here are some examples:
http://www.brigantesnation.com/SiteResearch/Iron%20Age/Carl%20Walk/CarlwarkWall.JPG (Unsupported image host)
http://www.traveladventures.org/countries/united-kingdom/images/windsor-castle10.jpg (Unsupported image host)
http://upload.wikimedia.org/wikipedia/commons/0/02/Kirchhain_defensive_wall.jpg (Unsupported image host)

Hope this helped!