To CMJ_Trans: What is obvious is that since the wall is burried, its base could be 7 feet underground. The "base of the wall" issue is totally irrelevant. You write: "where the wall WAS". Wrong: there IS a wall - underground.

The whole point in a nutshell: 1/ NO part of any wall is above ground and none is visible; 2/ aplomb means "right above" 3/ arasé means "razed and/or flush with the ground"; 4/ this whole story is driving me up the wall rofl!!:-)))

I mean a burried wall whose top is almost flush with ground level, covered with only a thin, drier layer of earth. Would be easier with a diagram!

I thought everybody was right until I read it a third time to realize that "murs arasés" are... "absent walls": on razed walls the grass growth thinner and shorter, hence provides a clue to archeologist to spot a vestigial wall and ruined city!