TITEL: Open space Mosques that change the urban environment In the twenty-first century, mosque architecture has undergone significant changes to respond to evolving social conditions and urban needs. This paper explores how contemporary mosques not only serve religious purposes but also interact with the social fabric of secular urban environments. The primary research question asks how mosque design can simultaneously address both religious and social functions required by the city, thereby transforming urban spaces and enriching social life. The central aim of this study is to propose strategies in contemporary mosque design that holistically address both religious and social needs. Historically, mosques have played a role in urban identity and development, serving as symbols of religious authority, tourism, and cultural heritage. However, architects today face a new challenge: creating spaces that align with contemporary ideologies and needs. This paper argues that a new architectural paradigm is emerging, one that replaces the enclosed, "city within a city" model of traditional mosques with open, multifunctional spaces that blur the boundaries between sacred and secular. In fact, contemporary mosque design is taking shape along an innovative path that transcends classical architectural parameters, using an interdisciplinary approach involving urban planning and sociology. This approach to open space in mosque architecture significantly influences activities both inside and outside the mosque, as well as how the mosque engages with surrounding urban spaces. This research employs a descriptive-analytical method with a developmental approach, drawing on library sources, field studies, and interviews. Findings are analyzed qualitatively, and the study's methodology is rooted in a multifaceted, interdisciplinary approach. By incorporating urban planning and sociology, it analyzes the mosque’s variable role within the urban landscape. This study situates this transformation within the time-space framework of the new millennium, where architectural responses to social change are actively rethinking and reinventing traditional religious structures. One case study is the Vali-Asr Mosque in Tehran. The design of its open spaces seeks to replace the traditional concept of the mosque as a closed unit, dissolving the boundaries between the sacred and the non-sacred. In designing this building, the architects integrated mosque architecture with the surrounding urban fabric and adhered to the "right to the city" concept, reinterpreting symbolic elements of the mosque for collective purposes. Traditional forms like the dome and minaret have been reimagined; for example, the dome, symbolizing unity and infinity, is designed as an accessible, curved roof that enhances interaction between the mosque and the public. The research findings indicate that through innovative architectural design, mosque open spaces can become dynamic social spaces that reflect new social and emotional needs. These transformations profoundly impact the role of religious architecture in secular societies, influencing how religious and social identities coexist and interact within urban landscapes.