1. Road map of the Boston district showing the metropolitan park system [cartographic material] Yale Public content 1900. 2013-04-03T15:22:02Z. 2018-09-05T19:51:35Z. Geo. H. Walker & Co., cartographer. Geo. H. Walker & Co. English. cartographic image. Public. Boston Metropolitan Area (Mass.), Massachusetts, Boston Metropolitan Area, and Boston Metropolitan Area.