This fully marshalled 24 km route includes climbing the highest point in the Brecon Beacons, Pen Y Fan, then descending to a turn around point. Then it's back over the ground you have already covered, back to the start point, 24km in all.

This is an incredibly tough challenge that has stood the test of time, and is very popular with those who wish to push themselves to their limits.

Candidates have the choice of 'tabbing' over the route with a 35lb bergen or running the course carrying just the bare essentials.

Once you have completed the challenge you will receive a custom First In medal.