Wally -bottom- and Albert -bottom-. The Blech patches are tufts of a very thick type of grass that grows on almost solid surface on north facing slopes. The slope we use to slide down is about 200 yds long and from top to bottom is about 100ft in height. Wally is almost at the bottom, the slope goes on up behind Albert for quite a long way. We usually sit on bits of cardboard, wood or plastic sheeting.