Since 1973 Ad Verheul is working at the Hartenberg Centre, an institute for profoundly mentally retarded people. This Centre belongs to the ‘s Heeren Loo Zorggroep, a large Dutch organisation for the mentally healthcare. He started as a therapeutic supervisor and after two years he was promoted to second manager of the department for Occupational therapy of the Hartenberg Centre. In 1976 he has designed and built a special playground for profoundly mentally handicapped people on the Hartenberg Centre. This was a very large project and very unique at the time. Ad Verheul and Henri Snel were talking about the future of ‘snoezelen’ and new ways of implementing it in care centers.