Nonradio, I flew into Nayland a few weeks ago. Afterwards, I walked the main runway and the following is just my estimate. Perhaps someone has the accurate surveyed figures?
I estimate the first 100m or so of r/w is fairly flat, followed by about a 100 foot rise in the next 200 m, (this is the bit you land on) followed by about 250 m of fairly flat ground past the hangers.
Again , this is only my estimate. Not difficult, and grass well kept and short.
I'm surprised no-one has mentioned Lundy Island. Very-rough surface with unyielding bits to avoid. You land across two fields passing through the gap in the stone wall. Unfortunately because of the curvature, you lose sight of the gap as you flare.
Plenty of nice short strips up in the Pennines. Watch out for the stone walls at the end !