In the Epic of Gilgamesh I believe that the walls of Great Walled Uruk were made 'all through of kiln fired brick'
http://www.shmoop.com/gilgamesh/pride-quotes-4.html
"Go up, Urshanabi, onto the wall of Uruk and walk around.
Examine its foundation, inspect its brickwork thoroughly—
is not (even the core of) the brick structure of kiln-fired brick,"