In general, central Ireland (but it's Great in Scotland) (4)
I believe the answer is:
glen
'it's great in scotland' is the definition.
I can't tell whether this defines the answer.
'in general central ireland' is the wordplay.
'in' means one lot of letters goes inside another.
'general' becomes 'gen'.
'central' says to take the centre.
The central letter of 'ireland' is 'l'.
'gen' going around 'l' is 'GLEN'.
'but' is the link.
Can you help me to learn more?
(Other definitions for glen that I've seen before include "Scottish mountain valley" , "Long narrow valley in Scotland" , "Narrow valley with a stream" , "Depression in Scotland" , "Narrow Scots valley" .)