Nowadays people can store various information in their personal devices because of development and popularization of electronic devices. Though the information can include the valuable contents for others, it remains in the devices unless the users take actions such as "sending." We are doing research on an environment called Urban Memories to distribute the valuable information stored in users' personal devices. In this environment, users exchange their information, such as "bookmark" and "memo," stored in their devices. However, it is difficult for users to retrieve valuable contents from the exchanged information because the exchanged information may be too much. In this paper, we propose a system for users to retrieve the valuable contents from the exchanged information through a map-based interface. This system organizes the exchanged information with three methods each of which focuses on relationship between place-information, person- information and person-place, and visualizes the exchanged information on a map. The system enables users to retrieve the valuable contents from the exchanged information in consideration of relations among person-to-person connection and characteristic of the information with this visualization.