The happening called La prohibición agradece (The Prohibition Thanks, 1972-1973) took place in the Colegio Mayor Santa Mónica (university residence) in Madrid in 1973 and was made up of several parts. On one of the walls in the entrance to the residence, Muro placed a series of photographs entitled Proyecto imposible de localización y análisis de las señales de prohibición situadas en el territorio nacional (Impossible Project of Locating and Analysing the Prohibition Signs Located on National Territory). The set of images showed a mapping of the country using signs and texts, with clear allusions to the regulatory and repressive framework of the State towards the end of the dictatorship. Muro was not a militant artist, nor did her work have a clearly anti-Franco content, as was the case with the work of other artists related to what was called "ideological conceptualism", but she did show an attitude of defiance to establishment power structures, whether State related, social or artistic.From the entrance the public had to move to the auditorium of the Colegio Mayor to prepare what was called the Libro blanco geometría de la Paz (White Book Geometry of Peace), a scathing reference to the white paper of the universities, an official document used by the institutions as an operational guide that laid the foundation for the future. In this case, by invitation from the artist, it would be written by the students themselves and woven from thoughts, theoretically unspeakable, and would be sealed when finished. At the end, the audience requested the content of the book be read aloud and then burned by the artist, which caused the sudden cancellation of the event and Muro's expulsion by the Colegio administration. The action establishes an ironic relationship between what was spoken and silenced, the secrets and the prohibitions, loaded with irony, which could become painful or even sinister.