I've just seen on SIentries a series of races called "The Drop", at various venues around Britain. They blindfold you and put you on a coach to a location 10 miles or 15 miles (you choose) from the Race HQ, where they take the blindfold off and leave you to find your way back. No map, phone or any other navigational aid allowed. You have a sealed emergency bag (which includes a GPS tracker, so you can be rescued); if unsealed, you are disqualified. A lot of the venues are large cities, but there's one at Hebden Bridge, which might be fun, especially if the drop-off location means that the fastest route back is across the moors. I have some knowledge of the area, and as a map-nerd I would enjoy spending hours on the 1:25000 South Pennines OS map, trying to memorise every road, path and track in a 10-mile radius of Hebden Bridge. Anyway, it's on my list of possible races.