We booked onto this site with the same purpose as another reviewer, to watch our son run in the London Marathon. Great connection to London Centre (Marylebone Station) on frequent Chiltern Railways service from Denham - takes between 25 and 30 mins deending on which train you get. One other warning, watch out which train you get as it stops at Wembley Stadium and if there's an event ending the tains do get rather full. The site was very clean and tidy with very friendly wardens. I haven't scored it high on facilities because there were only three showers in the male toilet block and this could be a bit limitingin high season. There is some noise from the very near local airport which you will notice during the day but we never heard anything at night so perhaps they don't allow night flying - could be an issue if you want to sleep in though. Others comments regarding access are quite valid and yuo definitely need to follow the diections on the club site and take care over the final 100 meters of approach. I would suggest that the barrier control for leaving the site could do with being relocated as it was difficult enough to reach it from the car running solo, so if you are single ahnded and towing a caravan you may well struggle. All in all, quite a good site and we will certainly stay here again if we need to visit central London.