The+Wall

Definition:

An upright structure of masonry, wood, plaster, or other building material serving to enclose, divide, or protect an area, especially a vertical construction forming an inner partition or exterior siding of a building.

Wall types:

-non-bearing walls: a wall construction that only has the purpose of supporting the weight of itself -bearing walls: a wall construction that supports the weight of the building

They are also divided into:

Retaining wall: is a wall built to support or prevent the advance of a mass of earth or water. Partition wall: is a wall for the purpose of separating rooms, or dividing a room. Defensive wall: is a fortification wall used to defend a city or settlement from potential aggressors.

Here is the link to a list of famous walls throughout history:

http://en.wikipedia.org/wiki/List_of_walls