This wall measured 462 feet long and 8 to 12 feet high. There were originally rooms most of the length of the wall, but by 1836 many of them were in ruins with only 3 to 4 blocks of rooms still intact and usable.

During mission period construction, there was an 11 ft. misalignment built outward on the northern sector of the wall. According to LaBastida, the intact rooms along the north wall were used as officers' quarters and an artillery command post and an armory workshop as described by Navarro. Jameson's account, verified by LaBastida's, indicates that the Alamo's headquarters and Travis' quarters were in one of the remaining blocks approximately midway down the wall.

There were at least two cannon located along the wall firing through embrasures. In the northern section of the wall, Jameson describes openings for cannon, but by the March 6th fall they were blocked up. It was through these blocked portholes that many of Cos's soldiers managed to gain entry into the compound. One of the ruined rooms along the west wall could be the "little fort" where the Béjar Alcalde, Francisco Ruiz described finding Crockett's body.