In this special 15th anniversary issue of Spectrum and video, a number of former and current staff share some of their personal memories of the journey since March 1997 when the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) began its operations in Vienna. In the words of the first Executive Secretary of the CTBTO, Wolfgang Hoffmann: ‘We were a very small group of people with a huge task. Although confronted with numerous challenges, many staff refer to the enthusiasm, optimism and team spirit which have made it all worthwhile and have enabled great progress to be made.’ Reflecting on the last 15 years, the CTBTO’s Executive Secretary Tibor Tóth concludes: ‘I think we can be proud that we have managed to deliver on things that were just dreams in March 1997 and to turn them into reality by spring 2012.