After my inital (massively hilarious) Post, I looked into this a joined the one in Cardiff. Signed up got email with the code and was in the gym half an hour after finding their website!
13.99 a month and £20 joining fee with no contract.
I am a bit of an insomniac so being able to go to the gym late at night suits me perfectly and there is enough free weights to keep me going for a while, only one squat rack though. Seems like a great idea so far.
No supervision at all at the times I go, just put in your pin number stand in an airlock pod thing and it let’s you in.