The rise of fast fashion has led to a surge in textile waste, with discarded clothing often ending up in unregulated landfills, posing significant environmental and social challenges. This has become a pressing global concern, as textile waste contributes significantly to pollution and land degradation. The study area covers an illegal clothing dump located near Iquique, Atacama Desert, Republic of Chile. This research focuses on mapping and analysing fast fashion landfill using remote sensing and Geographic Information Systems (GIS) to uncover the spatial and temporal dynamics of textile waste accumulation. By leveraging satellite imagery and spectral analysis, we identified the spatial extent and the "development" of the illegal clothing dump for the period from November 2016 to November 2024, highlighting their environmental footprint. Spectral analysis techniques were applied to distinguish textile waste from other materials using their unique spectral signatures. Temporal analysis further revealed trends in landfill growth, offering insights into the dynamics of textile waste accumulation.<br />This study emphasizes the utilization of open-source tools and freely accessible data to ensure reproducibility and accessibility. The adoption of open data and open-source software underpins the research's commitment to fostering transparency, reproducibility, and iterative improvements. By leveraging these resources, the study facilitates reusability and innovation in addressing similar environmental challenges. By demonstrating the utility of remote sensing and GIS as scalable, cost-effective tools for monitoring illegal waste sites, this study provides a framework for addressing similar challenges globally. This research also highlights the critical role of interdisciplinary approaches in tackling the complex environmental challenges.