Scenery that should not change over centuries
I believe the answer is:
stage set
'scenery' is the definition.
(thesaurus)
'should not change over centuries' is the wordplay.
I cannot really see how this works, but
'change' could be 'stage' (stage is a kind of change) and 'stage' is present in the answer.
The remaining letters 'set' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'that' is the link.
Can you help me to learn more?
(Other definitions for stage set that I've seen before include "play ready to start" , "Theatre scenery etc" , "Scenery and furniture" , "dramatic backdrop" .)