In December 1999, Chu Chang Jun, North Korea's longtime ambassador to China, repeated claims that a "wall" divided Korea. He said the south side of the wall is packed with soil, which permits access to the top of the wall and makes it effectively invisible from the south side. He also claimed that it served as a bridgehead for any northward invasion. One clarification in 2007, from an assistant of Mr. Cho at the Korean embassy in WDC, that this is mostly, or at least partly, an artificial cliff cut into the north side of the terrain, and explains this combination semantic and 'blind-men & elephant' issue. At the security passage between the North & South, it is easy to manage the contours and make the cliff invisible from the limited points of view allowed within the security compound. None of the plausible descriptions from the North, South, or USA, contradicts this explanation of the appearance or function of this at least partly one-sided wall.