Waymarking is a means by which people can catalog, mark, locate an log unique and interesting locations around the world, usually with a GPS receiver. Waymarking differs from geocaching in that there is no physical container to locate at the given coordinates. Waymarking identifies points of interest for GPS users. There are many categories of waymarks, such as Rails to Trails, Natural Arches, Natural Caves, Mountain summits, and Capitol Buildings. Participation in waymarking leads some to become more knowledgable of their own areas and to become interested in local history. Others have developed games (such as "What's in a Name?") that require the assistance of other players in remote areas.