From the start, within the walls of Portchester Castle, runners exit the castle onto Castle Street, before turning almost immediately right onto Waterside Lane, then running clockwise, around the outside of the castle walls, until once again they reach Castle Street. All runners then turn to their right, heading down Castle Street, before turning right into Hospital Lane. At the bottom of Hospital Lane, runners turn right, but bear left, and join the coastal path, heading west.
After 100 metres or so, runners continue running along the shorline, to the end of the grassy area, where they turn about and run back, but on the other side of the grassy area, towards the play area. On reaching the play area, turn left and run on the pavement, up Kenwood Road, to Wicor Path, where they turn right. At the very end of Wicor Path, runners crosss Castle Street, onto the pavement and turn left, heading up Castle Street, untill they reach Cow Lane (opposite Castle Street Primary School) where they turn right into Cow Lane.
At the end of Cow Lane runners bear left onto a path and head out towards the coastal path. On reaching the coastal path they turn right and continue along the path, continuing along the path, until they reach the slipway and the front of Portchester Sailing Club.
At this point, runners begin their second lap of the castle wall and continue as they did on lap 1. Once runners have completed their second complete lap of the course and have run around the outer castle wall for the third time, instead of runing back up Castle Street, they turn right back into the castle grounds, turning immediately right onto the field and onto the finish.