Moving out of doors with digital tools and electronic music and creating musically rich experiences is made possible by the increased availability of ever smaller and more powerful mobile computers. Composing music for and in a landscape instead of for a closed architectural space offers new perspectives but also raises questions about interaction and composition of electronic music. The work we present here was commissioned by a festival and ran on a daily basis over a period of three months. A GPS-enabled embedded Linux system is assembled to serve as a location-aware sound platform. Several challenges have to be overcome both technically and artistically to achieve a seamless experience and provide a simple device to be handed to the public. By building this interactive experience, which relies as much on the user's willingness to explore the invisible sonic landscape as on the ability to deploy the technology, a number of new avenues for exploring electronic music and interactivity in location-based media open up. New ways of composing music for and in a landscape and for creating audience interaction are explored.