National parks, crucial for nature-based tourism, often grapple with balancing marketing and sustainability objectives. Destination brand positioning offers a solution, yet techniques leveraging social media data for strategic positioning remain scarce. This research introduces a method, using Flickr photos, to: (a) identify the key features that define the brand identity of Thailand's national parks, (b) develop a categorical framework to group these parks based on their features and (c) uncover the distinctive features that differentiate parks within each identified category. Utilising Google Cloud Vision AI and LDA topic modelling, 51,387 photos across 125 parks were analysed, revealing 11 topics. K-Means clustering, supplemented by an innovative associative word analysis, discerned five park categories, and the distinctive features of each park. The findings advocate for Thai national parks to adopt strategies including brand positioning, repositioning, demarketing, and collaborative branding to harmoniously bridge sustainability and market demands. Management Implications•Association analysis can serve as an important tool for DMOs and conservation agencies to better understand and manage points of difference in nature-based tourism destinations.•The results of association analysis can inform brand positioning, repositioning, demarketing, and collaborative branding strategies that balance market needs with sustainability.•Distinctive brand positioning can be used to promote lesser-known destinations. Repositioning can be used to promote other strategic images and attributes of the destination. E.g., Khao Khitchakut National Park, which is famous for “Buddha footprint” can promote outstanding natural trails and wildlife that could attract high-value tourists. Demarketing may be necessary to conserve the uniqueness of certain destinations. We show some examples with overtourism that are put under great concern and should rely on carrying capacity strategies.