Virginia in old action organised on site (10)

'site' is the definition.
(excavation is a kind of site)

'virginia in old action organised' is the wordplay.
'virginia' becomes 'va' (US state abbreviation).
'in' means one lot of letters goes inside another.
'old' becomes 'ex'.
'organised' indicates an anagram.
'action' anagrammed gives '[action]'.
'ex'+'[action]'='ex[action]'
'va' inserted into 'excation' is 'EXCAVATION'.

'on' is the link.