It is surprisingly difficult to find a complete legend of all the map icons you might see on Google maps. Below is what was in a Google blog post from 2017 which corresponded with a feature release. This list is most probably not complete, but it was difficult enough to find that we decided to post it here for future reference. Below are the tables from Google’s announcement along with brief notes on ones to watch for in flight.
Outdoor and Transport
Airports are in the Transport category so you’ll want to keep an eye out for push pins with the plane icon in-flight. As you’ll see below Google uses several shades of blue for a variety of icons such as the Shopping push pins, which makes them a little tricky to spot. In the Outdoor category you can use the mountain icon to spot famous peaks, and often the hiking and park icons will lead you to scenic vistas.
Food, Shopping and Entertainment
The Entertainment and Leisure category often indicates sights that can be seen easily from the air. The Historic, Monument and Relic icons are typically used for famous landmarks such as castles and palaces as well as a variety of other historic places. Monument, Event Venue and Museum icons can be worth a look as well becuase many of these types of buildings use interesting architecture that can be seen from the air. Washington Monument in Wash, DC and Sydney Opera House would fall into this category.
Civil Services and Worship
The Civil Service and Worship categories can include some very interesting sites. In many parts of the world Churches and Temples are some of the most spectacular architecture in the area. Haigia Sophia in Istanbul, Notre Dame in Paris and Salisbury Cathedral in England would all fall into the Worship category. Also, bridges and dams would typically fall into this category so keep an eye out for those.
Services and Health
Services icons can be helpful as landmarks to help you find your position in-flight. Often hospitals, hotels and train stations can be easy to spot from the air. Also, hospitals often have helipads if you are flying a helicopter.
Color Legend
The color legend is not particularly helpful but it gives you and idea of how Google maps determines the color of the push pins. Unfortunately, half of them tend toward blue shades that all look pretty similar in flight. For example the Shopping and Transport are distinctly different shades of blue in the above image, but when the color is applied to a moving push pin on the map, with a white overlay of the icon it is a bit difficult to immediately discern the difference. But most of the types of icons that can be seen from the air fall into one of these categories, so the various blue shades are often worth a second look in-flight anyway.
The original blog post with this information is here https://www.blog.google/products/maps/google-maps-gets-new-look/