How to provide danger in alpine feature (4,6)

'alpine feature' is the definition.
(an alpine region might have a rock garden)

'how to provide danger' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'danger' is 'garden' which is located in the answer.
The remaining letters 'rock' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

'in' is the link.