Martin travelling round county (6)
I believe the answer is:
antrim
'county' is the definition.
(I've seen this before)
'martin travelling round' is the wordplay.
'travelling round' indicates anagramming the letters.
'martin' with letters rearranged gives 'ANTRIM'.
(Other definitions for antrim that I've seen before include "Irish county of musically green glens" , "NI town" , "County of Northern Ireland" , "Giant's Causeway county" , "18 down in Ulster" .)