Safe place for Hardy heroine to cross river (8)
I believe the answer is:
fortress
'safe place' is the definition.
(defensive structure)
'for hardy heroine to cross river' is the wordplay.
'hardy heroine' becomes 'tess' (in Tess of the d'Urbervilles, Thomas Hardy novel).
'to cross' means one lot of letters goes inside another.
'river' becomes 'r' (abbreviation for river).
'tess' going around 'r' is 'tress'.
'for'+'tress'='FORTRESS'
(Other definitions for fortress that I've seen before include "Strong point" , "Perhaps keep" , "Place that's secure" , "Secure building" , "Castle" .)