In order to overcome challenges related to orientation and mobility, visually impaired people need to know their environment. Tactile relief maps are generally used for exploring geographic information, but they retain significant limitations. Recent technological progress allows the development of interactive maps which overcome these limitations. We designed an accessible interactive map prototype composed by a multi-touch screen with tactile map overlay and speech output. It provided auditory information when tapping on map elements. We have demonstrated in an experiment that our prototype was more effective and satisfactory for visually impaired users than a simple raised-line map. We also explored and tested different types of advanced non-visual interaction (gestural, tangible and wearable) for exploring the map. Finally, we present how this work has been conducted using a participatory design process.