As part of the TACE project, a symposium was held between 27 and 29 October 2009 in Ljubljana, dedicated to the experimental theatre between 1945 and 2000, with a special focus on the spaces occupied by experimental theatres, or rather, the “occupying” of non-theatrical spaces, thus urbanising and socialising them. Contributors from all five participating countries took part. The papers in this publication are based and developed on those read at the symposium. The book Occupying Spaces is the result of successful cooperation between experts, co-ordinators and institutions from five countries. We should mention at least authors of contributed articles: - Czech Republic: Tatjana Lazorčáková, Vladimír Just and Tomáš Žižka, mamapapa o.s. (a civic association); - Hungary: Judit Csanádi, Borbála Szalai and István Nánay; - Poland: Joanna Ostrowska and Juliusz Tyszka; - Slovakia: Oleg Dlouhý, Maja Hriešik, Juraj Šebesta and Anna Grusková; - Slovenia: Tomaž Toporišič, Primož Jesenko, Barbara Orel and Ivo Svetina.