The not quite so sensible answer is a large, flat, roughly circular, field about 700-1000m on any dimension.
Granted you will have a big job on to mow it but you will always be able to take off and land into wind and the noise footprint will be well distributed. The run-off areas are almost limitless.
I believe this design worked well for the RAF for many years.
The Army still have one to this pattern (Middle Wallop).