Son looks round that place, finding lots of pieces (11)
I believe the answer is:
smithereens
'lots of pieces' is the definition.
'son looks round that place' is the wordplay.
'son' becomes 's'.
'looks' becomes 'miens' (mien can mean someone's look or appearance).
'round' is an insertion indicator.
'that place' becomes 'there' (I've seen this before).
'miens' going around 'there' is 'mithereens'.
's'+'mithereens'='SMITHEREENS'
'finding' acts as a link.
(Other definitions for smithereens that I've seen before include "Small broken pieces looked at together" , "broken bits?" , "Tiny fragments" , "Small fragments of the whole" , "Shattered fragments" .)