Winding path once leading to monument (8)
I believe the answer is:
cenotaph
'monument' is the definition.
(cenotaph is a kind of monument)
'winding path once leading' is the wordplay.
'winding' is an anagram indicator.
'leading' says to put letters next to each other.
'path' after 'once' is 'oncepath'.
'oncepath' anagrammed gives 'CENOTAPH'.
'to' acts as a link.
(Other definitions for cenotaph that I've seen before include "Monument to people whose remains are interred elsewhere" , "War memorial" , "Feature of Whitehall" , "Whitehall memorial" , "Monument to the war dead" .)