Understanding a large game space requires some type of visual. In most games, this visual is in the form of a map. Strategy games like Civilization V contain maps to help players continually orient themselves to where they are and where they need to go. Additionally, the map give a sense of progress and a sense of what still needs to be accomplished.
Maps provide the freedom to have non-linear movement through the game space, maps give the players the opportunity to decide where they would like to go next and what order to approach different parts of the game.
Most of the time the map provides a larger view of the area but often the player can then zoom into a particular area to see items in more detail and even use the map as a navigation device to move from one area to another.
While a game map may seem simple, it provides many different functions as indicated above, navigation, orientation, progress indicator and a visualization of goals yet to be accomplished.
When designing a learning game, consider how a map can help the learner to identify and approach learning goals and how it can help the player have a sense of autonomy by allowing her to move through the game space at her own discretion and order. Game maps are an integral part of a learning game and need to be considered carefully.