Fen Gallop 10K is a very nice cross-country 10 kilometers long race. It is my favorite one in Cambridgeshire. This run is halfway between a road race and a trail race and the route varies among these things: tarmac, grass, paths, ruts, dirt roads, mud, puddles, fields and wooded areas.
The race is organized on the first Sunday of July in Willingham, a village in Cambridgeshire about 15 km kilometers from Cambridge.
As this was only the second year when this race was organized it still had a few little problems, but overall it has improved since last year.
I recommend this and similar races to people that want to stay away from crowded road races or long trail races, want to be closer to the nature and want to challenge themselves on the technical paths..