do you mean map as in a minimap widget? or texture map? or UV maps? or mip maps? or input mapping? or the math concept of a linear function, which is also known as a map? or the programming concept of “an associative container that behaves like a dictionary”, which is also called a map?
maybe we should call them scenes. but then they would get confused with scene components, scene capture components, cut scenes, sequencer scenes, etc…
Levels could refer to adjusting the contrast in a texture, experience point levels, sound volume level, the angle of the ground being level, etc…
environment is probably the most clear word you could use, since people are unlikely to think you are talking about a development environment, or just talking about nature as in “save the environment.” and people who create these places are called environment artists.
you can say map, or you can say environment, but if you say environment map, you are talking about image based reflections…
Area? (math concept)
sector? (hard drive location)
region? (translation localization)
maybe we should call them zones? or stages? or worlds?