Old bar in Polish city (5)

I believe the answer is:

opole

I'm a little stuck... Click here to teach me more about this clue!

'polish city' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'old bar' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'bar' becomes 'pole'.
'o'+'pole'='OPOLE'

'in' acts as a link.

Can you help me to learn more?

I've seen this clue in The Hindu.

Want a hint initially instead of a full solution? Install my app