Oblivion Samhain begins at Kelvedon Hatch Secret Bunker near Brentwood in Essex. Runners start at 8:00am for a 24K obstacle race focused on repeated hard efforts. The format consists of three 6K laps, each containing over 70 obstacles. Racers cover the same distance multiple times as fatigue increases.
The course crosses rugged farmland, woodland, lakes, and mud, featuring both natural and man-made obstacles. It is chip-timed, and uncompleted obstacles incur no penalties, allowing participants to tailor the race to their ability, speed, and courage. This event is designed for experienced obstacle racers seeking a demanding test of endurance, strength, and mental fortitude, not a simple muddy run. Every finisher gets a medal, and Lucy Goodson is the organiser.