Maps are a type of activity that doesn't have a defined start or end time, so Smashers can ride on them anytime they want. Maps are also used for the creation of Playlists which are a series of back-to-back activities. Maps are continuously being improved and added.
Ask Smash Coach directly on the Home Screen what map you should try. He can suggest maps based on your preferences (e.g., climbing, flat, short/long, skill-based, etc.). You can also filter maps by duration, distance, and elevation gain under Explore in the hamburger menu > Maps > Filter. Sorting is also a useful function that allows you to sort Maps by Natural, New, Alpha, Intensity, Distance, Duration, and Elevation Gain.