Rocky Isle is a location on old European map (7)

I believe the answer is:

silesia

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'location on old european map' is the definition.
The definition suggests a singular noun which matches the answer.

'rocky isle is a' is the wordplay.
'rocky' indicates an anagram (letters rocked or thrown around).
'isle'+'is'='isleis'
'isleis' is an anagram of 'silesi'.
'silesi'+'a'='SILESIA'

Can you help me to learn more?

(Other definitions for silesia that I've seen before include "part of Europe" , "Region of central Europe" , "European region" , "Polish area" , "Central European area" .)

I've seen this clue in The Guardian.

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