Sustainable tourism is gaining in importance because of its ability to protect and promote environmental and cultural heritage, which are key factors in attracting tourists. It also entails meeting tourist demand while minimizing environmental impact and promoting integration between tourists and host communities. Since the early 1990s, with the United Nations World Tourism Organization (UNWTO) promoting the use of sustainable tourism indicators as essential instruments for policy making, planning, and management processes at destinations. The European Tourism Indicator System (ETIS) was launched by the European Commission in 2013 to help tourist destinations track and measure their sustainability performance. ETIS utilizes a four-pillar framework with 43 core indicators, providing a comprehensive yet flexible system for destinations to track their sustainability progress. Nowadays, the presence of infrastructure, such as ports, airports, and railways, plays a crucial role in influencing tourist flows transforming small, undiscovered cities into tourist hubs, by enhancing their accessibility. According to ONU Agenda 2030, tourism can serve as an incentive for the recovery of historical and cultural assets and environmental protection, but it can also exacerbate problems related to traffic, pollution, land use, and more. Considering this framework, the research focuses on assigning a weight to the indicators provided by ETIS and linking them according to the tourist flow influencing many small or undiscovered cities across Mediterranean area. As result the model not only informs sustainable tourism strategies but also equips policymakers with actionable data to foster long-term benefits.