Those travelling perhaps to ancient city -- it's enthralling son (8)
I believe the answer is:
tourists
'those travelling' is the definition.
(tourists frequently travel)
'to ancient city it's enthralling son' is the wordplay.
'ancient city' becomes 'ur' (ancient Sumerian city state).
'enthralling' indicates putting letters inside.
'son' becomes 's' (genealogical abbreviation for son).
'its' going around 's' is 'ists'.
'to'+'ur'+'ists'='TOURISTS'
'perhaps' acts as a link.
(Other definitions for tourists that I've seen before include "Group of visitors" , "Visitors and sightseers" , "Holiday-makers from abroad" , "They travel for pleasure" .)