There's plenty to be found in the Apennines (4)
I believe the answer is:
heap
'there's plenty to be' is the definition.
I can't tell whether this definition defines the answer.
'in the apennines' is the wordplay.
'in' indicates the answer is hidden within the clue.
'HEAP' is hidden within 'the apennines'.
'found' acts as a link.
Can you help me to learn more?
(Other definitions for heap that I've seen before include "Mound, stack" , "Pile (of scrap?)" , "good deal" , "Wreck of a car" , "Loose pile" .)