On 20 May 1981 there was an official opening ceremony at a Laboratory complex in Amsterdam including the high energy physic Laboratory, NIKHEF-H. On this occasion CERN set up an exhibition on its research. In the photograph touring the exhibition at NIKHEF are, left to right, A. Pais, Dutch Minister for Education and Science who opened the Laboratories, A. Diddens, Director of NIKHEF-H, I. Mannelli, CERN Research Director and R.F. Heyn, CERN Director of Administration. (Photo CERN 600.5.81)