It's probably well known that the onscreen maps that Ryo can buy in Shenmue 2 are stored as individual graphics files.
But it was quite surprising to find a map of a place where it's not possible to buy a map - the small port of Langhuishan in Guilin.
Map of Workers' Pier (used)
Map of Langhuishan (unused)
There are a few small differences in the location of some of the stalls and structures, although overall it's quite close to the actual location Ryo visits.
Blog post: http://www.phantomriverstone.com/2016/10/map-of-langhuishan-shenmue-2-unused.html