Looks like fun. I just stayed in Chelsea, right next to their team's clubhouse, but didn't even know about the maze of tunnels under my feet. Thats one more thing for my "to do" list for the next UK trip!
1. See the F1 race at Silverstone
2. Tour McClaren's factory
3. Attend Goodwood Festival of Speed Freaks
4. Visit Stonehenge
5. Tour Westminster Abbey
6. Explore the tunnels!
7. Ride the Eye of London
8. ????