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What is an Inset map

An easy-to-understand guide to Map Insets

Map Inset definition

A map inset is a small map or diagram that is positioned within a larger map to provide additional, detailed information about a specific area of the main map. The purpose of an inset map is to clarify, emphasize, or give context to a particular portion of the main map that might be too small or congested to show details clearly.

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There are several reasons why map insets are used:

  1. Scale Differences: If the main map covers a large area (e.g., an entire country) and there’s a need to show a detailed view of a smaller area (e.g., a city) within that country, an inset can be used to display that city at a larger scale.
  2. Isolated Areas: If territories or regions are geographically separated from the main area of interest (e.g., islands or exclaves), an inset can be used to show these areas without increasing the size of the main map.
  3. Context: An inset can provide geographical context. For instance, a map of a city might have an inset showing its location within the state or country.
  4. Additional Information: Insets can also be used to display thematic information related to the main map, such as a climatic zone or population density of a specific region.

Map insets help map readers get a more comprehensive understanding of the spatial relationships and details presented in the main map.

Examples of inset maps

  1. Global Perspective with a European Focus: Imagine a map showcasing the entire world, but there’s a smaller, detailed map specifically highlighting Europe. This smaller map zooms in on the various nations and major cities within Europe.
  2. Broad State View with a City Spotlight: Consider a map that displays an entire state. Within this map, there’s a smaller, detailed depiction of a particular city, showcasing its main roads, distinct neighborhoods, and notable landmarks.
  3. Park Overview with Specific Trail Details: Picture a map of a vast national park. Within this map, there’s a concentrated view of a specific hiking route or camping site, offering a closer look at its features and layout.
  4. Nation’s Layout with Island Insights: Visualize a map of a country, and within it, there’s a detailed representation of an island or a cluster of islands. This detailed view highlights the coastal structures and pinpoints towns and cities on these islands.

These inset maps serve as magnifying glasses, providing a closer look at specific regions within a broader geographical context.

What is the difference between an inset and a locator map?

Both “inset maps” and “locator maps” are tools used in cartography to provide context or additional information within a main map. However, they serve slightly different purposes:

Inset Map:

  • Purpose: An inset map is primarily used to show more detail of a particular area within the main map. It “zooms in” on a specific region to provide a clearer view of that area.
  • Scale: Typically, the scale of an inset map is larger (i.e., more zoomed in) than the main map to show finer details.
  • Usage: Commonly used in situations where a specific area on the main map is too small or congested to display details clearly. For instance, a map of the U.S. might have an inset map of Hawaii to show its details more clearly.

Locator Map:

A locator map, often referred to as a location map or reference map, is a simple map used primarily to show the location of a particular geographic area within its larger and more familiar context. Its main purpose is to help viewers understand where the primary focus of the main map or illustration is situated geographically. Locator maps provide a broader perspective to ensure that the audience can recognize and place the main area of interest in relation to more well-known regions.

  • Purpose: A locator map is used to show the location of the main map’s area of interest in relation to a larger context. It helps the viewer understand where the primary focus of the main map is situated geographically.
  • Scale: The scale of a locator map is usually smaller (i.e., more zoomed out) than the main map.
  • Usage: Commonly used in situations where the main map focuses on a region that might be unfamiliar to the viewer. For instance, a detailed map of a specific city might have a locator map showing where that city is located within its country or state.

In summary, while both inset and locator maps provide context, the inset map offers a detailed view of a specific area, and the locator map shows the broader geographical context of the main map’s focus.

About the Author
I'm Daniel O'Donohue, the voice and creator behind The MapScaping Podcast ( A podcast for the geospatial community ). With a professional background as a geospatial specialist, I've spent years harnessing the power of spatial to unravel the complexities of our world, one layer at a time.