Valley of the Kings the actual tomb of Tutankhamun (KV62) in November 1922. Various expeditions have continued to explore the valley, adding greatly to the knowledge of the area. In 2001 the Theban Mapping Project designed new signs for the tombs, providing information and plans of the open tombs. The earliest tombs were located in cliffs at the top of scree slopes, under storm-fed waterfalls (KV34 and KV43). As these locations were filled, burials descended to the valley floor, gradually moving back up the slopes as the valley bottom filled with debris. This explains the location of the tombs KV62 and KV63 buried in
Valley of the Kings and KV46, although both KV62 and KV46 were robbed soon after their actual closure) were undisturbed during this period. Most of the tombs are not open to the public (18 of the tombs can be opened, but they are rarely open at the same time), and officials occasionally close those that are open for restoration work. The number of visitors to KV62 has led to a separate charge for entry into the tomb. The West Valley has only one open tomb—that of Ay—and a separate ticket is needed to visit this tomb. The tour guides are no longer allowed to