... according to the aerial view of the camp (see below) this photo could be the southern border of the camp with the alignment of the two watchtowers. The muddy road -- a deep moat was dug by the Japanese after Hummel & Tipton's escape from the camp. That trench was a complementary protection against further escapes (?) ... or was it the ideal place for a hasty burial place (?)...
... click on the picture (above) for the next view ...