Posts Location taxonomy is available for default WordPress blog Posts, each blog post can be assigned to one or more Locations.
To add new or find your created Location navigate to Posts > Locations via the main WordPress menu.
For each Location can be defined name (title), parent of Location if you are creating a parent-child hierarchy of Locations, and also description text which can tell more about created Location in short.
Created locations are available in the Posts Search Form block to search through posts by specified Location.