Urban public spaces play a significant role in meeting human needs and enhancing social interactions. These spaces serve as primary settings for urban events and gatherings of diverse social groups. However, many public spaces suffer from shortcomings that hinder their attractiveness and functionality, resulting in low levels of user presence. To better understand these deficiencies and propose effective strategies to enhance vitality and increase public presence, it is essential to study changes in human activities over different time periods. This research focuses on the forecourt of the Karim Khan Citadel (Arg-e Karimkhani) in Shiraz as a case study. The study aims to investigate the impact of public events on changes in human activities within this urban space, through a comparative analysis of conditions during the Nowruz festival and the post-event period. Adopting a field-based, descriptive-analytical approach, the research seeks to answer how human activities are transformed during and after an event, and which spatial features influence these changes. To build the theoretical framework, a literature review was conducted using documentary methods, and five key variables were selected: activity patterns, activity nodes, types of activity, duration of presence, and movement paths. In the methodological phase, the hypothesis was tested through Jan Gehl’s behavioral mapping techniques such as tracking, tracing, note-taking, and direct observation in two timeframes—during and after the event. By analyzing the collected data with a focus on the selected variables, the study attempts to logically interpret the dynamics of human activity associated with the presence or absence of events. The findings reveal that cultural and social events significantly increase the vibrancy, diversity, and density of collective activities in the space, particularly encouraging the participation of women and children. However, once the events conclude, these indicators visibly decline. Moreover, spatial design, environmental conditions, and temporary design elements play a critical role in shaping the quality and duration of user presence. Based on the results, the study recommends the regular organization of public events along with improvements in the environmental quality of the forecourt space, to enhance its liveliness and social effectiveness as an urban public space.