After a loop around Castle Acre the route follows the Peddars Way to the coast at Holme next-the-Sea, before following the coastal path all the way to Sheringham and the finish at Beeston Hall School.
There will be a 16 hour time limit – all competitors finishing by 11 pm.
Race forms part of Positive Steps Grand Slam. The other races are Kings Forest 50 km and Peddars Way Ultra. All three events must be completed in any order in a 12 month period to be awarded the Grand Slam tankard.