What was “the ascent to the armory at the buttress”?

We are to understand that there was a higher portion of land inside the walled area upon which an armory was located, a place where weapons were stored (think spears, bows, and arrows that could be rained down upon enemies below; remember that this portion of the wall was on the edge of a precipice). The term translated as buttress literally means angle or corner and so describes a point in the wall that’s strengthened by virtue of an angle (though not necessarily a sharp angle). Ezer reinforced the wall that stood below this ascent.