A castle king's set up on tableland (5)

I believe the answer is:

karoo

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

'tableland' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?

'a castle king's set up' is the wordplay.
'castle' becomes 'r' (abbreviation for rook/castle in chess).
'king' becomes 'k'.
'set' indicates anagramming the letters (instruction to set the letters).
'up' becomes 'oo' (I can't explain this - if you can you should believe this answer much more).
'a'+'r'+'k'='ark'
'ark' with letters rearranged gives 'kar'.
'kar'+'oo'='KAROO'

'on' is the link.

Can you help me to learn more?

(Another definition for karoo that I've seen is " High plateau in South Africa".)

I've seen this clue in The Telegraph.

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