the scale is 5mm is to 2ft not 5mm:1ft.
topography wise, the creek is at elevated position than trees B and C.
the creek cuts the slope horizontally. the slope runs east to west.
facing downstream which is north, the area at your right is a flat land.
i'm telling this to give more perspective to the decoders.
burrowing at the side of the creek and placing the object at the center of the creek is a Japanese repertoire and this idea troubles me a lot because it is hard to operate.
or if the object is placed at the downslope side of the creek (the other side is more elevated), could it be possible that they dug the creek (dry during summer) and burrow to the lower side so when they retrieve it, they just break the thinner wall and bingo? hope somebody could share some of his experiences about this matter.
thanks