Yep Darren's right - 3 times up Box Hill I'm afraid @Whorty ! Here's the Strava segment - https://www.strava.com/segments/19636443 - my PR for it is 1:05:48, but that was done on the Bkool Pro so I'll expect to be a few minutes slower than thathttps://zwiftinsider.com/london-loop-box-hill-finish/
It is indeed 3 times up Box Hill, finishing at the top on the last lap hence 2.5 laps.