Geographic roles
Right-click a field → Geographic Role and assign country, state, city, postcode, airport or a custom role.
Tableau generates Latitude and Longitude fields and can then map the dimension. Double-clicking a geographic field builds a map automatically.
Ambiguous locations
An indicator in the bottom right reports unrecognised or ambiguous values — Paris exists in France and in Texas.
Click it → Edit Locations to resolve them, either by supplying a parent region (country, then state) or by matching each unknown value manually.
Setting the parent region — putting Country above City — resolves most ambiguity automatically and is quicker than editing values one at a time.
Custom geocoding
Tableau does not geocode arbitrary addresses. For locations it does not know — store numbers, sales territories, warehouse sites — you supply coordinates yourself.
Create a CSV with your location names and their latitude and longitude, then Map → Geocoding → Import Custom Geocoding pointing at the folder.
The role then appears alongside the built-in ones. You can extend an existing role — adding your own regions to the country role — or define an entirely new one.
Polygons and territories
Supplying polygon points plus a sequence field lets Tableau draw custom shapes — sales territories, delivery zones, store catchments. The sequence tells it the order in which to trace the outline.
Balance detail against speed: highly detailed polygons slow a workbook considerably, and at typical zoom levels the extra precision is invisible.
Map layers
Map → Map Layers toggles background detail — streets, boundaries, terrain, data layers such as population.
Recent versions also support multiple marks layers on one map: sales as filled regions with store locations as symbols on top. Drag a second geographic field onto the view and choose Add a Marks Layer.