Click Photo for Larger Version
View looking south at the southern side (baulk) of Kathleen Kenyon’s large western trench at Old Testament Jericho.
At the time of Kenyon’s excavations (1960’s), the sides of this trench were perfectly vertical, and she could "read" the cutaway view of what she had dug through.
This picture was taken forty years later and it is clear how over this period of time the mud brick side of the trench has disintegrated—and Jericho only receives 6 to 8 inches [15-20 cm.] of rain each year.
This image courtesy of Reinhold Buxbaum.