Six American spies surrounding rocky hill station (8)
I believe the answer is:
victoria
'station' is the definition.
(Victoria is a major railway station in London)
'six american spies surrounding rocky hill' is the wordplay.
'six' becomes 'VI' (Roman numerals).
'american spies' becomes 'CIA' (Central Intelligence Agency).
'surrounding' means one lot of letters goes inside another.
'rocky hill' becomes 'tor' (I've seen this before).
'cia' enclosing 'tor' is 'ctoria'.
'vi'+'ctoria'='VICTORIA'
(Other definitions for victoria that I've seen before include "Capital of the Seychelles" , "She falls in Africa" , "Queen (eighteen thirty seven to nineteen hundred and one)" , "Queenly" , "Monarch" .)