London Marathon volunteering, so just one route published

To the Green Bridge  (10.97km / 6.82ml run)

Car Park, Rose Garden, Forty Hall, Maidens Bridge, Bulls Cross, Spurs, Trail round back of Theobalds, St Mary's School, Green Bridge, New River Trail, Maidens Bridge, Forty Hall Trail, Car Park

https://gb.mapometer.com/running/route_5277077

Want to go further?  Go left and St Mary's school and follow Bury Green Rd, Dark Lane, Goff's Lane and Churchgate and pick up the new River trail just before the Crocodile Public House. It brings you our by the Green bridge.