Greensand Ridge Relay
This is a 6 leg relay from Leighton Buzzard to Northill (near Sandy) with legs varying from 3.9 – 9 miles. The teams aim to complete the course by 4:30pm and their start time is determined by a preset handicap based on age and gender. The website for the event can be found here: https://www.smoc.info/GSRR/gsrr.htm.
There is also an option to do the run as a solo. This is in the region of 34 miles!