Feature of Riyadh, an oil-rich capital (5)

I believe the answer is:

hanoi

'capital' is the definition.
(Hanoi is an example)

'feature of riyadh an oil-rich' is the wordplay.
'feature of' indicates the answer is hidden within the clue.
'HANOI' is hidden in the letters of 'riyadh an oil rich'.

(Other definitions for hanoi that I've seen before include "Capital city of Vietnam" , "capital out East" , "Vietnamese capital" , "Asian city" , "Asian capital on the Red River" .)

I've seen this clue in The Guardian.

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