The Berlin Wall was more than long. In June 1962, a second, parallel fence, also known as a “hinterland” wall (inner wall), was built some farther into East German territory. The houses contained between the wall and fences were razed and the inhabitants relocated, thus establishing what later became known as the "death strip". The death strip was covered with raked sand or gravel, rendering footprints easy to notice, easing the detection of trespassers and also enabling officers to see which guards had neglected their task; it offered no cover; and, most importantly, it offered clear fields of fire for the Wall guards.