Nature-based tourism in the fragile Arctic environments is emerging as a major environmental concern, mainly due to extreme seasonality in these locations, the lack of suitable infrastructures and planning, and its interference with fragile ecosystems. In Iceland tourism has increased exponentially during the past decades, causing more environmental impacts on the country's natural recourses. Hiking is one of the most popular tourist activities in Iceland, especially in the interior highlands. This study had two goals: to map the current status of hiking trail conditions in two popular tourist destinations of the southern highlands, Pórsmörk and Fjallabak Nature Reserve (FNR); and to examine the relationship between trail condition assessment and local physical properties, such as elevation, gradient, soil type, and vegetation cover, in GIS. The current status of the hiking trails is much worse in the Pórsmörk area, where over 30% of the trail system is classified as being in bad and very bad condition, compared to 12% for the FNR. Of the analyzed physical properties only elevation has a clear relationship with hiking trail condition in both study sites and gradient in the Pórsmörk area. Importantly, severe conditions never apply to a whole trail, suggesting that trail conditions are a function of trampling magnitude and local physical properties. Hence, when maintaining hiking trails in vulnerable environments, such as the Icelandic highlands, a holistic understanding of the environmental impact of trampling is critical. Management implications When nature-based tourism enters very fragile environments, good monitoring techniques become even more important. Such is the case on hiking trails in the highlands of Iceland, where the study produced the following findings: Monitoring the conditions of hiking trails is vital for understanding the major causes of trail degradation in the Icelandic highlands. Implementing a visual field assessment with a condition scale based on simplified classification system, a whole trail system can easily and cost-effectively be monitored and changes recorded. Visual interpretation of the spatial patterns of a trails' condition can further aid managers to identify problem areas and to avoid this type of area in future planning.During new trail design, steep slopes should be avoided as trampling easily intensifies solifluction and thus contributes to soil instability and soil erosion. In flat areas trails should be designed so hikers do not easily walk off the trails and thus increase the area of their impact.Inevitably, the number of users contributes the most to trail degradation. Therefore in the most vulnerable areas of the highlands the flow and number of tourists should be restricted.Gathering high resolution geographical data for use in Geographical Information Systems (GIS) are important in order to monitor and track changes of hiking trail conditions. The possibilities to analyze spatially distributed data and relationships between variables further provides better understanding of cause and effect regarding tourism impact in sensitive natural environments.