Use Tableau Map Layers to Plot US and Global Cities

Contributed by: Christopher Gardner

Difficulty level: Intermediate

Tableau maps are a beautiful way to illustrate geographic data. Incorporated within the software is an underlying database with latitude and longitude information to plot countries, states, provinces, counties, cities, and more.

For cities, Tableau can plot any location with a population above 10,000 people; however, this flexibility leads to potential issues. For example, there are 33 Clevelands in the world, and 28 of them are located within the United States! This means that data for cities that are ambiguous like “Cleveland” needs an additional level of detail to determine which city is being referenced. Tableau illustrates this with a notification on the map once it is plotted.

Figure 1.

If you click on the error, you get the opportunity to provide details about the ambiguous city’s location. If your data contains additional geographic data, you can use these fields to provide context to Tableau about where the city is located. This works in most situations, but there are some situations where the context can cause issues as well.

Let’s look at an example. Imagine you have a dataset with geographic data containing cities for both the US and elsewhere in the world. This sounds simple to plot on a map, but it is surprisingly challenging. The context window ...