Valley of the Kings rains. There is currently little year-round rain in this part of Egypt, but there are occasional flash floods that hit the valley, dumping tons of debris into the open tombs. The quality of the rock in the Valley is inconsistent, ranging from finely-grained to coarse stone, the latter with the potential to be structurally unsound. The occasional layer of shale also caused construction and conservation difficulties, as this rock expands in the presence of water, forcing apart the stone surrounding it. It is thought that some tombs were altered in shape and size depending on the types of rock the
Minor tombs in the Valley of the Kings are larger, multiple chambered tombs. These minor tombs served various purposes, some were intended for burials of lesser royalty or for private burials, some contained animal burials and others apparently never received a primary burial. In many cases these tombs also served secondary functions and later intrusive material has been found related to these secondary activities. While some of these tombs have been open since antiquity, the majority were discovered in the 19th and early 20th centuries during the height of exploration in the valley. Tombs in the Valley of the Kings are assigned a numerical "KV" (for Kings' Valley)