This chapter presents the SketchMap system, which supports children’s situated learning by their experience of creating maps. In an outdoor environment, each child creates a map in the region of his or her school using a SketchMap client. The map is uploaded to the SketchMap server to be shared with other children who have created maps of different areas. Children can add new information to the maps or can edit them in their classrooms or in their homes. The goal of the SketchMap project is to investigate whether it the integration of outdoor and classroom activities, and the sharing of the children’s experiences through the maps, can actually promote collaborative learning. This system has been used in the classes “safety map” and “nature exploration” in a Japanese elementary school, and an evaluation of the system has also been performed. Some issues that were identified during the educational activities are also described here.