Below; Welsh town (5)
I believe the answer is:
neath
I believe this clue is a double definition.
'below' is the first definition.
(I've seen this before)
'welsh town' is the second definition.
(I've seen this before)
(Other definitions for neath that I've seen before include "Welsh industrial town" , "Under (poetic)" , "Town near Swansea" , "town in South Wales" , "Town NE of Swansea" .)