A cross reality system enables any of multiple devices to efficiently access previously stored maps. Both stored maps and tracking maps used by portable devices may have any of multiple types of location metadata associated with them. The location metadata may be used to select a set of candidate maps for operations, such as localization or map merge, that involve finding a match between a location defined by location information from a portable device and any of a number of previously stored maps. The types of location metadata may prioritized for use in selecting the subset. To aid in selection of candidate maps, a universe of stored maps may be indexed based on geo-location information. A cross reality platform may update that index as it interacts with devices that supply geo-location information in connection with location information and may propagate that geo-location information to devices that do not supply it.