The observatory of the Réal Collobrier basins was set up in 1967 to improve the knowledge of particular hydrological phenomena in the Mediterranean area. Located in forest and rural areas on metamorphic soils of the Massif des Maures in the Var, it is a landmark of regional hydro-climatology. This laboratory is used to develop research on improving the knowledge of Mediterranean hydrology, with a monitoring of rainfall (currently 17 raingauges) and flow (7 water level recorders) on a 70 km² basin, since more than 50 years. A Scientific Interest Group, the GIS Réal, conducted multidisciplinary research between 1990 and 1994. The members of this GIS group included hydrologists, hydraulic engineers, geologists, geographers, geomorphologists, geochemists from various universities and research organizations. Since then, several European research projects have tackled different themes on the spatial knowledge of rainfall fields and the setting up of a flood warning system. Since 2015 the watershed has integrated the SOERE RBV and IR OZCAR. New measuring instruments have been set up (multi-parameter probes, meteorological station, water temperature, automatic sampler, etc.). Scientific objectives around the observatory include the study of flash floods, availability of water resources, study of the interaction between vegetation and the water cycle, knowledge of spatial variability of hydrometeorological processes. These interdisciplinary research axes call for hydrology, soil physics, geomorphology, hydrogeology and biochemistry contribute to the improvement of knowledge, the development of tools and methods in the field of rainfall and climatology, and also to the improvement of the understanding and the modelling of the flows.