Situated in Japan, the Onsenji temple (8)
I believe the answer is:
pantheon
'situated in japan the onsenji temple' is the definition.
I can't judge whether this definition defines the answer.
'in japan the onsenji temple' is the wordplay.
'in' indicates the answer is hidden within the clue.
'PANTHEON' is hidden in the letters of 'japan the onsenji temple'.
Can you help me to learn more?
(Other definitions for pantheon that I've seen before include "All the gods of a people or religion" , "Temple of all the gods in ancient Greece" , "list of great names" , "church" , "Circular temple in Rome" .)