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
Exploration of the Valley of the Kings original tomb owners. In tomb KV17, they removed wall decorations, which are now on display in the Louvre in Paris. In 1845-1846 the valley was explored by Karl Richard Lepsius's expedition; they explored and documented twenty-five in the main valley and four in the west. The second half of the century saw a more concerted effort to preserve rather than simply gathering antiquities. Auguste Mariette's Egyptian Antiquities Service started to explore the valley, first with Eugène Lefébure in 1883, then Jules Baillet and Georges Bénédite in early 1888, and finally Victor Loret in 1898 to 1899. Loret added a further