It’s not that simple to get to Skreens Park Campsite but here are some pictures to help you along the way.
The entrance is here: https://www.google.co.uk/maps/place/51%C2%B044’54.0%22N+0%C2%B020’35.7%22E/@51.748344,0.3410593,17z/data=!3m1!4b1!4m5!3m4!1s0x0:0x0!8m2!3d51.748344!4d0.343248
and looks like:
My suggestion for a route:
M11 South to J8
Take the B1256 towards Great Dunmow
At Takley turn right down the B183 South towards Hatfield Broad Oak then Hatfield Heath
In Hatfield Heath turn left and Take the A1060 East to Boyton Cross
In Leaden roding follow the road round to the right.
Turn right just after the Garage and follow the road.
At Elms Road turn right and follow until you reach the site on the left
Overview Map: