Ancient monument single female visits gets vandalised (10)
I believe the answer is:
stonehenge
'ancient monument' is the definition.
(I've seen this in another clue)
'single female visits gets vandalised' is the wordplay.
'single' becomes 'one' (a single thing - only one).
'female' becomes 'hen' (female chicken).
'visits' is an insertion indicator (inserted letters visit the inside of another word).
'vandalised' is an anagram indicator.
'one'+'hen'='onehen'
'gets' anagrammed gives 'stge'.
'onehen' inserted into 'stge' is 'STONEHENGE'.
(Other definitions for stonehenge that I've seen before include "Druid comes here" , "Wiltshire prehistoric monument" , "Wiltshire attraction" , "Salisbury Plain circle" , "Ancient monument site" .)