The security structure in Tabran Toos

Toos has been one of the most important regions of Khorasan until the end of 8th century and it contained four cities the  most largest of which has been Tabran. Since Tabran was located at the eastern borders of Iran and different tribes attacked it frequently,  the issue of security has been of the most important concerns for kings and people in this city. By Promoting Islam in Iran and persisting on people security, Iranians had been familiar with various ways to supply their security and implemented it in their cities. The present research aims to examine methods to supply security in Tabran emphasizing on the structure of palisades and city gates, by studying historical texts and obtained reports from archeological explorations. The results from field activities and library sources indicate that the structure of foundations, wall's wide diameters, wall slopes and usage of high quality materials and also government policies and attendance of guards have been effective in the security of Toos Tabran.  The palisades and city gates were effective elements to supply the security of people lives and properties against alien attacks. In order to achieve the research purpose the historical method with a qualitative approach along with documentary sources analysis and field activities had been applied.