Developed under the auspices of UNESCO, SESAME (Synchrotron light for Experimental Science and Application in the Middle East) will be a major international research center in the Middle East and Mediterranean region where most of the applications require hard x-rays up to 20 keV photons. At the 6th of January 2003 the official foundation of SESAME as well as the ground breaking for the building took place. The accelerator SESAME is based upon the synchrotron light source BESSY I, which was, with the operation of BESSY II, devoted to SESAME. The original plan was to upgrade BESSY I to an energy of 1 GeV and use superconducting wigglers to reach 20 keV photons. According to the present design SESAME will be a 2.5GeV 3rd Generation light source with an emittance of 24.6 nm.rad and up to 13 places for the installation of insertion devices with an average length of 3.1 meters. The circumference of the machine will be 124.8 m. As injector the 800 MeV Booster Synchrotron of BESSY I will be used with minor changes. At SESAME around 39.7% of the circumference can be used for the installation of insertion devices. At the beginning of operation 6 beam lines should be installed.