The Institute of Engineering Seismology & Earthquake Engineering (ITSAK) is a research center established in 1979. It has been operating free field strong motion instruments on a national scale (consisting of more than 96 instruments) and a special 3D strong motion array in the Euro-SeisTest. Moreover, two permanent special arrays on structures are maintained by the staff of ITSAK, those of Evripos cable-stayed bridge and a building at Thessaloniki.