Title: The Effect of the Geographical Factors on the Foundation, Development and Destruction of TABARAN TOUS city

Different factors are impressive in foundation and development of an urban circumference that undoubtedly between them, Geographical and environment factors have the most important role. The TOUS or KASHAFROOD plain in KHORASAN in which the ruined city of TABARAN TOUS is located enjoys many of desired environmental factors such as abundant water principals; existence of springs and seasonal rivers, good weather, fertile soil, rich herbaceous cover and green pasturages has caused attraction and settlement of human groups from old times. Old stones tools discovered in this plain and KASHAFROOD borders belong to lower Paleolithic and existence of archaic caves in plain border and before historic and after historic settlement are good evidences in this connection. Further more location of TABARAN TOUS near the borders of central Asian tribes had granted a sensitive location to this town as a strategic military area in middle ages. But with development of MASHHAD city from 8th century after hijrah, city of TABARAN had lost its strategic location and with transfer of GILAS spring water to MASHHAD that one of the most important principals of safeguarding of TABARAN water, desired geographical factors differed in this region and this city abandoned for ever. In this paper I have tried to survey effect of factors on foundation and development of this city in Middle Islamic Ages and also its destruction and abandonment after 8th century after hijrah which were rooted that it caused according to geographical factors.