This spaceborne radar image is being used by archaeologists to study geographical factors that influenced the cultural developments of Petra, Jordan. For the past 10,000 years, the Petra region has been the site of some of the most important cultural developments in the history of humankind. Early agriculture and metallurgy were practiced here, and links were forged in a trading network that stretched from East Asia to Europe. These events are remembered in sacred stories, and today the region is a part of what adherents to the Muslim, Jewish, and Christian religions consider their homeland. Limestone highlands, the purple area in the lower right, were forested areas before the trees were cut down. The center area (green and orange) is a region of canyon-cut sandstone steppes. Important sources of water originate in the bright band that forms the boundary between these two geological regions. These springs were used by human settlements established in the canyon area, including the one of the earliest agricultural villages in the world, Beidha, as well as, the Nabataean caravan trading city of Petra, Roman fortifications, and Crusader castles. The dark region in the upper left is Wadi Araba, the geographic extension of the Great Rift Valley in east Africa. It marks the boundary between the modern states of Jordan and Israel and has been used as a corridor for traveling human populations, including our pre-Homo Sapiens ancestors, for many millennia. This image was acquired by Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR- C/X-SAR) onboard the space shuttle Endeavour on April 9, 1994. The colors are assigned to different radar frequencies and polarizations: red is L-band, horizontally transmitted and received (LHH); green is L-band, horizontally transmitted and vertically received (LHV); and blue is C-band HV. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Earth Science Enterprise.