The Notre Dame is history making itself physically known to us. We draw upon its presence to acknowledge and express human achievement.The cathedral has always been an operative building, despite all misfortunes, serving the people for centuries as a functional and living essence of the city and it will continue to do so as long as people are engaged with it.The present proposal aims to follow its programmatic essence as a building that is both engaged and engaging, operative and adaptable. The highest honor a building can have is to be lived by the people and to shape the city in a positive way. Therefore, the space on the roof was thought of as a public library, aimed to be an international Archive for books on Theology and general knowledge, as well as a section for local books. The roof is divided into 2 floor and originates alternating niches that allow for a greater variety of interior and exterior reading spaces. The exterior concrete structure follows the logic and rhythm of the buttresses created by the gothic cathedral and adds a layer of support to the roof and spire. Finally, the entire structure of the roof is converted into a glass framed structure, which serves two purposes: granting the interior space abundant natural light and intensifying the connection to the outer world, the city of Paris. At night, the roof and the spire light up, giving back to the city as a permanent lighthouse, always present, where people can look to as a symbol of hope, memory and the future to come.The Notre Dame is history making itself physically known to us and a permanent source of knowledge that we can embrace.