A secret surfing location? (4,3)

I believe the answer is:

dark web

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

'a secret surfing location?' is the definition.
I know that 'surfing' relates to this answer.

'secret surfing location?' is the wordplay.
'secret' becomes 'dark' (I can't explain this - if you can you should believe this answer much more).
'surfing location?' becomes 'web' (as in surfing the web).
'dark'+'web'='DARK WEB'

Can you help me to learn more?

I've seen this clue in The Times.

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