Group of rocks, in a single layer, gets moved outside (10)
I believe the answer is:
stonehenge
'group of rocks' is the definition.
The definition suggests a singular noun which matches the answer.
'single layer gets moved outside' is the wordplay.
'single' becomes 'one' (a single thing - only one).
'layer' becomes 'hen' (hens lay eggs).
'moved' indicates anagramming the letters.
'outside' indicates putting letters inside (some letters go outside others).
'gets' with letters rearranged gives 'stge'.
'one'+'hen'='onehen'
'onehen' put into 'stge' is 'STONEHENGE'.
'in a' is the link.
Can you help me to learn more?
(Other definitions for stonehenge that I've seen before include "Salisbury Plain circle" , "Wiltshire attraction" , "Megalithic monument on Salisbury Plain" , "Wiltshire landmark" , "rock group" .)