Miniature three-dimensional scene (7)
I believe the answer is:
diorama
'miniature three-dimensional scene' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for diorama that I've seen before include "museum feature" , "A little set" , "Model representing a scene with three-dimensional figures" , "Miniature scene with figures" , "Scene with models" .)