At Enigma Fireworks, runners circle Caldecotte Lake repeatedly: 7.5 clockwise laps for the marathon or 3.5 for the half. The two-day event is based beside the lake in Milton Keynes, near the hotel and pub car park area, and each day offers both distances in November.
The format is straightforward: everyone runs clockwise on the same lake loop, with water and toilets available every lap. Course details are provided at the venue, runners must attend a briefing ten minutes before the start, and the race team includes a starter, timekeeper, and referee. Marathon finishers have a 7-hour cutoff.