See pic of Caldecott Juniors camped at Screens Park, Scouting Centre, near Chelmsford, Essex, about 1991, from an old CA calendar, also elsewhere.
I recall a basic junior camp in June 1961 at a field in part of Mersham by the East Stour river. By the benevolence of Mr. Kirwan-Taylor, the same field was used for junior camps each year up to 1981 (when, as was common, there was wet weather, as mentioned in Mr. Ian Lovett's brief account in the CC newsletter).
In summer 1982 the field was not available, hence junior camp was at hut accommodation in Screens Park, Scouting Centre near Chelmsford, Essex. Going by Mr. John Daly's account in the CC newsletter, it had a medieval-type tower with ropes and pulleys for abseiling or as an aerial runway, with adventure scouts instructing. There was also a small lake, canoeing, fishing, nature trailing, camping and bivouacking, with good food. No surprise that this was to be the place for Caldecott junior camp for several years.

IAN LOVETT writes on JUNIOR CAMP 1981 (a tribute to Caldecott endurance)
"And the Director spoke unto certain of the staff and commanded them to organise and equip a gathering of the junior members in a small field to the south(?) of the main house".
“Make for yourselves various waterproof shelters" sayeth the Director. "Take three hundred cubits of canvass, fifty cubits of nylon string (for the making of guy ropes) and 30 cubits of sausages (so that they shall eat in plenty) - for there shall be a great flood upon all the earth lasting approximately 5 days" - And it was so!!
Nevertheless Junior Camp 1981 had its high spots. There was little or no need to wash at night, making gravy for stews proved to be unnecessary, and all the tents had a good wash!!
JOHN DALY writes on JUNIOR CAMP
The siting of our Junior Camp has for years been by the river in Mersham, but this year the field was no longer available to us and it was decided to go to Screens Park which is a Scouting Centre near Chelmsford in Essex.
With some trepidation we loaded supplies and bodies into three vans and off we went. We found an Aladdin's Cave for campers. After the Monsoon-type weather we had experienced in recent years in Mersham we were delighted to find hut accommodation provided at the new site. There was also a small lake which attracted all the children, who spent hours playing in what to them was warm weather, and a few hardy adults who seemed ever watchful for icebergs and polar bears.
A medieval torture tower which the children happily swarmed up and down, using ropes and pulleys for absailing or as an aerial runway, also posed terrifying problems for the adults who dangled grotesquely from ropes or clung in a death grip to wobbly ladders. Fortunately there were adventure scouts on hand to do the instructing.
There was also canoeing, fishing, nature trailing and just plain Camping. By way of variation there was bivouacking, which for those who do not know (and that was all the adults present bar one) seems to consist of lying freezing in a hedge all night!
Our especial thanks to Mary and Dorothy who provided a campfull of ravenous wolves with enough good food to keep them from eating each other (made more likely by the appetites nurtured in that busy outdoor world).
Looking back the camp was a great success which was not the least due to Dennis Brown, our very able Camp Organiser, and to everyone, grown up and child, who made it such a memorable experience for us all.