Google Earth imagery is used here in conjunction with a Geographic Information System to identify transverse drainages and recreate palaeodrainage in an internally draining region in Iran. At least 35 water gaps and 34 wind gaps are shown to exist in the region, as well as evidence for an integrated palaeodrainage that originated north of the internally draining region and emptied into the Mand watershed to the west. The topographic characteristics of the transverse drainages suggest a strong control by local topography, and support formation of the internally draining region by basin filling and overflow. Both climatic and tectonic factors may have controlled the loss of external connectivity.