Pile of wood set on fire, watched from behind chain (8)

I believe the answer is:

pyrenees

I'm a little stuck... Click here to teach me more about this clue!

'chain' is the definition.
(I know that Pyrenees is a chain)

'pile of wood set on fire watched from behind' is the wordplay.
'pile of wood set on fire' becomes 'pyre' (I can't explain this - if you can you should believe this answer much more).
'watched' becomes 'seen' (I've seen this before).
'from behind' is a reversal indicator.
'seen' written backwards gives 'nees'.
'pyre'+'nees'='PYRENEES'

Can you help me to learn more?

(Other definitions for pyrenees that I've seen before include "Mountains between France and Spain" , "Mountain range in southwest Europe" , "French/Spanish mountains" , "European mountains" , "Mountain chain between France and Spain" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.