||Nature-based tourism and recreation are ecosystem services that have the potential to benefit human wellbeing, as well as local economies (Haines-Young and Potschin, 2010). They can therefore represent an important political argument to conserve and restore nature areas (Schirpke et al., 2018). However, for these contributions to be acknowledged, they should first be monitored. The number of visits to nature areas has been recognised as one of the major indicators to assess nature-based tourism and recreation (Schägner et al., 2018). Visiting frequencies are, for example, crucial for the estimation of economic contributions. However, for diffuse nature areas with multiple entry and exit points, this data is often scarce, scattered and imprecise. Recently, innovative technologies have allowed to obtain more continuous and/or detailed data for both small and larger areas (Kellner and Egger, 2016). Our research used two of those methodologies to estimate visitor frequencies in nature areas: 1) an analysis based on passive mobile phone positioning data and 2) automatized image analysis based on photos issued from camera traps. Our case study area concerns the Ardenne forests, located in southern Belgium (Walloon region) for the period spring 2018 – summer 2019. The aim of this research is to improve ecosystem services assessments concerning nature-based tourism and recreation and, by doing so, facilitate ES being taken into account by site managers and policy makers in the sustainable management of nature areas.