Here are two videos walking through how to create a 3D diorama, block diagram looking thing.
This one is for land: https://youtu.be/kVsj6Z7UuLY
This one is for undersea scenes: https://youtu.be/ehJhR3lgjNw
Folks have been making these and sharing the results and they are a total blast. My favorites are those that use imagery on the surface. Give it a go if you are feeling dangerous.