Giuseppe, Massimiliano and Massimiliano, Vito and Armando were just boys that summer evening in 1993, when, sitting on the stairs of the Sant'Anna church, in the heart of Cagliari, they were reflecting on the beauty of their city. Next to the cathedral, the archaeological museum, the art gallery, the most important and famous churches, the city had guarded an incredible heritage of towers, churches, ancient buildings, crypts and important, extraordinary monuments were by that time closed to the public. Among their peers no one had ever climbed, for example, on one of the city towers, no one had ever admired the sumptuous rooms of the Viceroy Palace. Very few of them had entered the hypogeum of Santa Restituta: the last ones to have seen those spaces, sixty years before, had been the citizens terrified by the rain of bombs that the English and American planes had unloaded over the city in 1943, during the Second World War. What treasures, they thought, were hidden in the small church’s Hope? Which were the secrets inside the Masonic House? Which were the wonders in the castle of San Michele or in the San Saturnino church? A world rich in memory, guardian of a common history of exchanges, meetings, passages, happy and dark moments, too precious to be kept still hidden. That evening they were just boys, fantasizing about their own future and how beautiful it would be to re-open the closed monuments and return to Cagliari its history and experience. Why don't we try it? The five boys founded the cultural association called "Ipogeo" and they presented themselves to the parish priest of Santa Restituta church, asking permission to open the crypt, clean it from years of neglect and show it to the public. For two years, between 1994 and 1996, with a group of young people and students, they told the story of the crypt, used since ancient times, dedicated to the cult of the martyr Restituta and finally used as an air-raid shelter in those dramatic months of the bombing of Cagliari. Ten thousand visitors flock to the site on the 126 consecutive Sundays to get to know this monument, so famous but never visited before! And then they got the keys of the Speranza, San Lorenzo and San Pietro churches among others, which were also unknown to the population. For two whole years the "Ipogeo" cultural association, in a completely voluntary way, opened, cleaned, removed the dust of abandonment and finally lived those spaces, together with the entire community. And at that point, “the five” wondered: why not dream even bigger? Just from the Santa Restituta crypt, through a press conference in the spring of 1996, "Ipogeo" launched a challenge to the city: let's reopen all the closed monuments, let's show them, let's tell their stories. Don’t let resign ourselves to a destiny of neglect, don’t let the loss of memory cloud our communities. Let's join forces of volunteers and associations and take back that incredible heritage from our grandparents. After that conference came a first, good news: there will be the support of the City of Cagliari and the Superintendence of cultural heritage. Thanks to them they will have the keys of the sites and the permits to welcome the public, in addition to the invaluable help for communication. And so, on the weekend of May the 10th and 11th 1997, the first edition of Cagliari "Monumenti Aperti" (“Open Monuments”) was born: 36 museums, palaces, archaeological sites and cultural spaces were visited by 15.000 people, welcomed by over 600 volunteers who offered guided tours. The doors of Cagliari, finally, were open to all. The "Ipogeo" cultural association did it, the challenge was won! Since then the event has spread to the whole island of Sardinia (it has reached also the region of Apulia, Lombardy, Piedmont and Emilia-Romagna) and has changed its name to "Open Monuments". This great event has not missed an edition and now involves 60 municipalities, 20.000 students, hundreds of cultural associations, pro loco associations, committees, managed by the big organization of "Imago Mundi". Since those first 36 monuments were opened in 1997, today there are more than 800, and guided tours are no longer managed by a small group of friends but by 23.000 guides including pupils, students and volunteers. They were just kids then, and they would have never imagined that the dream they were dreaming about that summer evening would come true.