Picturesque cave (6)
I believe the answer is:
grotto
'picturesque cave' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for grotto that I've seen before include "Fancy cave" , "Attractive natural, or artificial, cave" , "In company (with); over length of" , "Cavern" , "(Imitation) cave" .)