A map is an essential tool in your genealogical research.
It not only helps you to locate specific places or geographic features,
but it allows you to identify the specific geopolitical entity that has
(or historically had) jurisdiction over an area.
It also helps you visualize a large geographical area,
thereby giving you the "big picture" and perhaps an insight into migration
patterns that played a part in your ancestors' movements. You should
certainly be using maps, gazetteers, and drawings in conjunction with one
another to help solve the riddles of "lost" or "missing" towns.
Please also remember that archives, libraries, government
offices, and other archives that act as repositories for current and
historical maps can be another resource for you. Don't hesitate to contact
them for assistance.