In reply to UKC Articles:
Strictly speaking, Castle Hill basin is all the limestone in the um, basin.
If you do end up going, respect the rock and don't wire brush or chalk foot holds etc as the polish in quantum field is already taking its toll on some classics. Take a piece of carpet or beer towel to clean shoes before stepping onto the rock.
Some of my fondest climbing memories involve CH.
Cheers Derek for the cool vid!!